CA2397961C

CA2397961C - Pyrido[2,3-d]pyrimidine-2,7-diamine kinase inhibitors

Info

Publication number: CA2397961C
Application number: CA002397961A
Authority: CA
Inventors: Richard John Booth; Ellen Myra Dobrusin; Vara Prasad Venkata Nagendra Josyula; Dennis Joseph Mcnamara; Peter Laurence Toogood
Original assignee: Warner Lambert Co LLC
Current assignee: Warner Lambert Co LLC
Priority date: 2000-01-25
Filing date: 2001-01-23
Publication date: 2008-08-26
Anticipated expiration: 2021-01-23
Also published as: HUP0204141A3; CR6706A; BR0107751A; NO20023527D0; IS6443A; CN1395578A; DZ3266A1; PA8510701A1; PL356802A1; AR030044A1; WO2001055147A1; TNSN01014A1; OA12161A; HN2001000013A; ZA200205879B; MXPA02007221A; MA26868A1; KR20020065939A; JP2003523357A; SV2002000294A

Abstract

Disclosed are compounds of the formula (I) wherein: R2, R7, R13, R14 and R15 are independently hydrogen, or (un)sub-stituted lower alkyl, (un)substitued lower alkenyl, (un)substituted lower alkynyl, or (un)substituted -(CH2)n R12; R5 is halogen, cyano, nitro, -R9, -NR9R10, or -OR9; R6 is halogen, cyano, nitro, -R9, -NR9R10, -OR9, -Co2R9, -COR9, -CONR9R10, -NR9COR10, (un)substi-tuted lower alkenyl, or (un)substituted lower alkynyl; R8 is - CO2R13, -COR13, -CONR13R14, -CSNR13R14, -C(NR13)NR14R15, -SO3R13, -SO2R13, -SO2NR13R14, -PO3R13R14, -POR13R14, -PO(NR13R14)2; R9 and R10 are independently hydrogen or (un)substituted lower alkyl; R11 is a heteroaryl or a heterocyclic group; R12 is a cycloalkyl, a heterocyclic, an aryl, or a heteroaryl group; and n is 0,1,2, or 3. These compounds and their pharmaceutical compositions are useful for treating cell proliferative disorders, such as cancer and restenosis. These compounds are potent inhibitors of cdks and growth factor- mediated kinases.

Description

PYRIDO[2,3-d]PYRIMIDINE-2,7-DIAMINE KINASE INHIBITORS
FIELD OF THE INVENTION

This invention relates to pyrido[2,3-d]pyrimidine-2,7-diamines that inhibit cyclin-dependent serine/threonine kinases and growth factor-mediated tyrosine kinase enzymes, and as such are useful to treat cell proliferation diseases and disorders.

BACKGROUND OF THE INVENTION
Summarv of the Related Art Cell cvcle kinases are naturallv occurrina enzvmes involved in regulation of the cell cycle (Meijer L.. "Chemical Inhibitors of Cyclin-Dependent Kinases,"
Progress in Cell Cycle Research, 1995;1:351-363). Typical enzymes include serine/threonine kinases such as the cyclin-dependent kinases (cdks) cdkl, cdk2, cdk4, cdk5. cdk6, as well as tyrosine kinases involved in cell cycle regulation.
Increased activity or temporally abnormal activation or regulation of these kinases has been shown to result in development of human tumors and other proliferative disorders. Compounds that inhibit cdks. either by blocking the interaction between a cvclin and its kinase partner. or by binding to and inactivating the kinase, cause inhibition of cell proliferation. and are thus useful for treating tumors or other abnormally proliferating cells.
Several compounds that inhibit cdks have demonstrated preclinical antitumor activity. For example. flavopiridol is a flavonoid that has been shown to be a potent inhibitor of several types of breast and lung cancer cells (Kaur et al., J. 1Vatl. Cancer Inst., 1992:84:1736-1740; Int. J. Oncol., 1996;9:1143-1168).
The compound has been shown to inhibit cdk2 and cdk4. Olomoucine [2-(hvdroxyethvlamino)-6-benzylamine-9-methvlpurine] is a potent inhibitor of cdk2 and cdk5 (Veselv et al.. Eur. J. Biochem., 1994;224:771-786), and has been shown to inhibit proliferation of approximately 60 different human tumor cell lines used bv the National Cancer Institute (NCI) to screen for new cancer -~-therapies (Abraham et al., BioloD, of the Cell. 1995;83:105-120). More recently.
the purvalanol class of cdk inhibitors has emerged as more potent derivatives of olomoucine (Gray N.S. et al.. Science. 1998:281:533-538).
Tvrosine kinases are essential for the propagation of growth factor signal transduction leading to cell cvcle progression. cellular proliferation, differentiation, and migration. Tyrosine kinases include cell surface growth factor receptor tyrosine kinases such as FGFr and PDGFr, as well as nonreceptor tvrosine kinases. including c-Src and lck. Inhibition of these enzymes has been demonstrated to cause antitumor and antiangiogenesis activity (Hambv et al., Pharmacol. Tlier.. 1999; 82(2-3):169-193 ).
Several pyrido[2.3-d]pyrimidines that inhibit cdks and gromh factor-mediated kinase enzymes are known (WO 98/33798). US Patent Nos. 5.733,913 and 5,733,914 describe 6-aryl-pyrido[2.3-d]pvrimidines.
Despite the progress that has been made, the search continues for low molecular weight compounds that are orally bioavailabie and useful for treating a wide variety of human tumors and other proliferative disorders. including restenosis, angiogenesis. diabetic retinopathy. psoriasis. surgical adhesions, macular degeneration. and atherosclerosis. The present invention provides such compounds, their pharmaceutical formulations. and their use in treating proliferative disorders.

SUMMARY OF THE INVENTION

This invention provides novel pyrido[2.3-d]pyrimidine-2.7-diamine compounds which function as inhibitors of cell cycle regulatory kinases such as the cyclin dependent kinases as well as the growth factor-mediated tyrosine kinases. Thus, these compounds are useful to treat cell proliferative disorders such as atherosclerosis and restenosis: cancer: angiogenesis: viral infections including DNA viruses such as herpes and RNA viruses such as HIV: fungal infections;
type 1 diabetes. diabetic neuropathy and retinopathy: multiple sclerosis;
glomerulonephritis: neurodegenerative diseases including Alzheimer's disease;
autoimmune diseases such as psoriasis. rheumatoid arthritis. and lupus; organ , -~-transplant rejection and host versus graft disease; gout; polycvstic kidnev disease:
and inflammation including inflammatory bowel disease.
Accordingly, the present invention provides pyrido[2,3-d]pyrimidine having the generic structure of Formula I

r; XIN XN > HNN R7 R2 Rg wherein:

R2, R7, R13, R14 and R15 are independentlv hvdro(yen, or lower alkyl, lower alkenyl, or lower alkynyl, each of which is optionally substituted with up to 5 groups independently selected from halogen, cyano, nitro, -R9, -NR9R10, -OR9. -(CH2)nCO-)R9, -(CH-))nSO2R11, -(CH,))nRl1, -COR9, -CONR9R10, -S03R9, -SO2NR9RIO, -SO-)R9, -SR9. -PO;R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO,~ R10, -NR9CONR9R10, -NR9SO-)R10, or a heterocvcle optionally substituted with up to 3 groups independentlv selected from -R9, -NR9R10, -OR9.
-NR9COR10, -COR10, -(CH-))nSO-)RI l, -(CH-))nRl1, or -(CH2)nRlI optionally substituted with up to 5 groups independently selected from halogen, cyano, nitro, -R9, -NR9R 10, -OR9, -(CH-))nCO-)R9, -(CH-))nSO-)R11, -(CH2)nR11. -COR9.
-CONR9R10, -SO-R9, -SO,)NR9R10. -SO-)R9. -SR9, -PO;R9R10, -POR9R10, -PO(NR9R10)2. -NR9COR10.
-NR9CO-)R10. -NR9CONR9R10, -NR9SO-)RIO. or a heterocvcle optionally substituted with up to 3 groups independentlv selected from -R9. -NR9R10, -OR9.
-NR9COR10, -COR10. -(CH2)nSO--)RI 1, -(CH-))nR11;
R5 is haloizen. cvano. nitro. -R9, -NR9R 10, or -OR9:

R6 is halogen. cvano. nitro, -R9, -NR9R10, -OR9. -C02R9. -COR9, -CONR9R10. -NR9COR10, -SO-)NR9R10, -SO2R9. -S03R9, -SR9.
-P03R9R10. -POR9R10. -PO(NR9R10)2, or lower alkenyl or lower alkvnyl optionally substituted w=ith -R9;

R8 is H. -CO2R1'. -COR13, -CONR13RI4. -CSNR13R14, -C(NR1')NR14R15 -S03R1', -SOiRl', -SO-)NR13R14 -P03R13R14, -POR13R14 -PO(NR13R14),,;

R9 and R10 are independently hydrogen, or lower alkvl, optionally substituted with up to 3 groups selected from the aroup consistina of halogen. amino, mono- or dialkylamino, hvdroxv. lower alkoxy, phenvl or substituted phenvl, or when taken toQether with the nitrogen to which they are attached, R9 and R10 form a rinR having from 3-7 members, up to four of which may be selected from 0. S. and NR20, where R20 is hvdrocen, loxver alkyl. or -CO lo,~ver alkvl:

Rl I is a heteroaryl or a heterocyclic group:

Rl' is a cvcloalkvl, a heterocvclic. an arvl, or a heteroarvl group;
nis0, 1,2,or3:
and the pharmaceuticallv acceptable salts, esters, amides, and prodrugs thereof.
The present invention also provides a composition that comprises a compound of Formula I together with a pharmaceuticallv acceptable carrier, diluent, or excipient.
The present invention also provides methods for inhibiting cyclin-dependent kinase and grow-th factor-mediated kinase enzymes.

-J-The present invention also provides a method of treating subjects suffering from diseases caused by cellular proliferation. The method comprises inhibiting proliferation of tumorigenic cells of epithelial origin and vascular smooth muscle proliferation, and/or cellular migration by administering a therapeutically effective amount of a compound of Formula I to a subject in need of treatment.
The present invention also provides a method of treating subjects sufferina from diseases caused bv DNA tumor viruses, such as herpes viruses comprising administering a compound of Formula I.

DETAILED DESCRIPTION OF THE INVENTION

The compounds encompassed by the instant invention are those described bv the general Formula I set forth above, and the pharmaceutically acceptable salts, esters. amides, and prodrugs thereof.
In addition to the compounds of Formula I. the invention provides preferred compounds of Formula II:

~,T a~" ~ / R

HIv' N N N
I II

wherein R5. R6. R7. and R8 are as defined above for Formula I;

R16. R17. and R18 are as defined above for the (CH-))nRl2 substituents, and preferably are independently hydrogen. halogen. amino. mono- or dialkvlamino. hvdroxv, lower alkyl. lower alkoxv, cvano, nitro, carboxy, carboxvalkvl. aminocarbonyl, mono- or dialkylaminocarbonyl, alkvlcarbonyl. -SO;R9, -SO~NR9R10, -SO-)R9, -SR9. -PO;R9RI0, -POR9R10, -PO(NR9R10)'), -NR9COR10, -NR9CO~R10.
-NR9CONR9RI0. -NR9SO,)R10; or R16 is a carbocyclic group containing from 3-7 members, up to ? of which members are heteroatoms selected from oxygen and nitrogen, wherein the carbocyclic group is unsubstituted or substituted with 1, ?. or 3 groups as defined above, but preferably are independently selected from the group consisting of halogen, hvdroxv, lower alkvl, trifluoromethyl, lower alkoxy.
amino, mono- or dialkvlamino, aryl, heteroaryl, arvlalkvl, heteroarylalkyl, heteroarvlsulfonyl, heteroarvlsulfonylalkvl, heterocyclvlalkyl, heterocvclvlsulfonvl. or heterocvclvlsulfonvlalkvl.

Preferred compounds of Formula Il are where R5 is hydrogen or lower alkyl; R6 is hydrogen, lower alkyl, cvano or halogen; R17 and R18 are independently hydrogen, halogen, amino, mono- or dialkylamino, hydroxy, lower alkyl, lower alkoxy, aminocarbonyl, mono- or dialkylaminocarbonyl, -SO2NR9R10 or -NR9COR10; and R16 is optionally substituted N-piperidine, N-piperazine, or N-pyrrolidine, for instance where the rina substituents are selected from -R9, -NR9R10, -OR9. NR9COR10. and COR10.
In addition, the present invention also provides preferred compounds of Formula III:

N
~
R~1 HN N N N III
1 R2 IIN~O

wherein R2. R5, and R6 are as defined above for Formula I; and R 19 is hydrogen, or lower alkyl, lower alkenyl. or lower alkynyl, each of which is optionally substituted with up to 5 groups independentlN, selected from halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy.
cyano, nitro, carboxy, carboxyalkyl. aminocarbonyl. mono- or dialkvlaminocarbonyl, lower alkvlcarbonvl, -SO3R9, -S02NR9R10, -S02R9. -SR9, -PO;R9R10, -POR9R10.

-PO(NR9R10)2, -NR9COR10, -NR9C02R10. -NR9CONR9R10, -NR9SO2R10, where R9 and RIO are as defined above, or aryl. heteroaryl, arvlalkyl, heteroarylalkyl. cycloalkyl or cvcloalkyl-alkvl, where each aryl, heteroarvl or cvcloalkyl group is optionally substituted with up to 5 groups independently selected from halogen, amino, mono- or dialkvlamino, hvdroxy, lower alkoxv.
cvano, nitro, carboxy, carboxvalkyl, aminocarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyl, -S03R9, -SO2NR9R10, -S02R9, -SR9. -P03R9R10, -POR9R10, -PO(NR9RIO)2, -NR9COR10, -NR9C02R10, -NR9CONR9R10, -NR9SO2RI0, or a(CH2)n-carbocyclic group containing from 3-7 members, up to 2 of which members are heteroatoms selected from oxygen and nitrogen, wherein the carbocyclic group is unsubstituted or substituted with 1. 2. or 3 groups independently selected from the group consisting of halogen, hvdroxy, lower alkyl. trifluoromethvl, lower alkoxv, amino. mono- or dialkylamino, arvl, heteroarvl, arylalkyl, heteroarvlalkyl, heteroarvlsulfonyl, heteroarylsulfonvlalkvl, heterocyclvlalkyl, heterocyclylsulfonyl, or heterocvclvlsulfonvlalkvl; and R21 is hvdrogen, lower alkyl. or lower alkyl substituted with phenyl or substituted phenvl.

Preferred compounds of Formula III are where R5 is hydrogen or lower alkvl. R6 is hvdrogen or halogen. Rl- is optionallv substituted phenyl; R21 is hydrogen or methyl: and R 19 is optionally substituted lower alkyl, cycloalkyl, or (CH-))n-carbocvclic.

An especially preferred group of pvrido[2.3-d]pyrimidines have Formula IV:

lT ~ \
~ R7 ..1 I-I?'' N N IiT IV
C=0 18 FfN
R

wherein R5, R6. R16 R17 R18 R19 and R21 are as defined above. Preferred compounds of Formula IV are those wherein R21 is hvdrogen or methvl.
Another especially preferred group of invention compounds have Formula V:

R') 1"T
N
~
R_1 HN N N N V
R1 ~ R18 C=O
T

R

wherein R5, R6, R 16. R 17. R I S. R 19. and R21 are as defined above.
Preferred compounds of Formula V are those wherein R21 is hydrogen or methyl.
The most preferred invention compounds have Formula VI

N
HNI Nr N N-H or alkvl C=0 I
alkvl or cvcloalkvl N
R2-, R?2 ' H or alkanovl wherein R5. R6. R 17, and R 18 are as defined above, and R2 2 and R23 independently are hydrogen or alkyl.
By "alkvl," "lower alkyl," and "(C I-C I 0)-alkyl" in the present invention is meant straight or branched chain alkyl groups having 1 to 10 carbon atoms, preferably CI-C6 alkyl. Typically alkvl groups include methyl, ethyl. n-propyl, isopropyl. n-butyl. sec-butyl, tert-butvl. pentyl, 2-pentyl, isopentvl.
neopentyl, hexyl. 2-hexyl, 3-hexyl, decyl, octvl, and 3-methvlpentyl. These groups may be substituted. for instance with halo. C I -C - alkyl. amino, alkvlamino, dialkylamino, hvdroxy. alkoxy. and the like. Examples include chloromethyl, 2-amino-ethyl, and 3-dimethvl-aminopropyl.
Bv "alkenyl." "lo,~ver alkenyl." and (C-)-C I O)-alkenyl is meant straight or branched chain alkyl groups having I to 10 carbon atoms and having 1 or 2 nonadjacent double bonds. Examples of alkenvls include, but are not limited to, 3-butenyl and I -methyl-3-pentenyl.
Bv "alkynyl," "lower alkynyl." and (C-)-C I 0)-alkynyl is meant straight or branched chain alkvl groups having I to 10 carbon atoms and having a triple bond. Typical alkynvl groups include 2-propynyl and 1.1-dimethvl-3-butynyl.
Substituted alkenvl and alkvnyl groups include 4.4-dibromo-2-pentenyl and 3-amino-5 -hexvnvl.
Bv "alkoxy.- "lower alkoxy." or "(C I-C I 0)-alkoxy" in the present invention is meant straight or branched chain alkoxy groups having 1 to 10 carbon atoms. such as. for example. methoxy. ethoxy. propoxy, isopropoxy. n-butoxy, sec-butoxy, tert-butoxy, pentoxy. 2-pentyl. isopentoxy, neopentoxy. hexoxy.
2-hexoxy, 3-hexoxv. and 3-methylpentoxy.
The term "alkanoyl" means an alkyl group bonded through a carbonyl moiety. Examples include acetyl and pentanoyl. "Aminoalkanovl- means the alkyl group is substituted with an amino group. Examples include aminoacetyl and 3-aminohexanovl. "Alkylaminoalkanovl" means an aminoalkanoyl group wherein the amine is substituted with a C 1-C 10 alkyl group, and includes methylaminoacetyl and 4-(isobutylamino)-octanoyl. "Dialkvlaminoalkanoyl"
means an N.N-di-substituted aminoalkanoyl group such as diisopropylaminoacetyl.
By halogen in the present invention is meant fluorine, bromine, chlorine, and iodine.
The term "aryl" means an unsubstituted aromatic carbocvclic group having a single ring (e.g., phenyl), multiple rings (e.g., biphenyl), or multiple condensed rings in which at least one is aromatic (e.(Y., 1,2,3,4-tetrahvdronaphthyl, naphthyl, anthryl, or phenanthryl). The term "substituted aryl'' means an aryl substituted by 1 to 4 substituents selected from alkyl. 0-alkyl and S-alkyl. -OH, -SH, -CN, halo, 1.3-dioxolanvl, -CF;, -NO2, -NH2. -NHCH;, -N(CH3)2, -NHCO-alkyl, -(CH2)mCO2H, -(CH2)mCO2-alkyl, -(CH2)mSO;H. -NH alkyl, -N(alkyl)2, -(CH2)mPO3H2, -(CH2)mPO3(alkyl)2, -(CH2)mSO2NH2, and -(CH2)mSO2NH-alkyl. wherein alkyl is defined as above and m is 0. 1. 2, or 3. Some examples of substituted aryl groups are methylphenyl. isopropoxyphenvl, chlorophenyl, 2-bromo-3-trifluoromethvl-4-nitro-5-aminophenvl. 4-bromobiphenyl, 3-acetamidonaphthyl, 3-dimethylaminoanthryl. 3.4-dimethoxyphenanthryl, and 2,8-dibromobiphenylen-l-vl.
By "heteroaryl" is meant one or more aromatic ring svstems of 5-, 6-, or 7-members containing at least I and up to 4 heteroatoms selected from nitrogen, oxygen, or sulfur. Such heteroaryl groups include, for example, thienyl, furanyl, thiazolyl, imidazolvl. (is)oxazolyl. tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyrazolyl, (iso)quinolinyl, napthyridinyl, phthalimidyl, benzimidazolyl, benzoxazolyl. A"substituted heteroaryl" group can be substituted with 1, 2, 3, or 4 of the groups mentioned above for "substituted aryl." such as 2.3.4.6-tetrachloropyridvl and 2-methoxy-3-trifluoromethvlthien-4-yl.
The term "heterocvclic group" means a non-aromatic ring having 5-. 6-. or 7-ring atoms, from I to 4 of which are selected from nitrogen. oxygen. or sulfur.
Examples of heterocyclic groups include morpholino, piperidino. piperazino.
pvrrolidinyl. and tetrahydrothienyl. Such groups can be substituted with the same groups described above for substituted heteroaryl.
A"carbocyclic group" or "cycloalkyl" is a nonaromatic cyclic ring or fused rings having from 3- to 7-ring carbon members. Examples include cyclopropyl, cvclobutyl, and cycloheptyl. These rin--s may be substituted ,vith one or more of the substituent groups mentioned above for arvl, for example alkvl, halo, amino, hvdroxy, and alkoxy. Typical substituted carbocvclic groups include 2-chlorocyclopropyl, 2.3-diethoxycyclopentyl, and 2.2,4,4-tetrafluorocvclohexyl.
The carbocyclic group may contain 1 or 2 heteroatoms selected from oxygen, sulfur, and nitrogen, and such ring systems are referred to as "heterocyclyl"
or "heterocyclic". Examples include piperidyl, piperazinyl, pyrrolidinyl, pyranyl, tetrahydrofuranyl, and dioxanyl. These heterocyclyl groups may be substituted with up to 4 of the substituent groups mentioned for aryl to give groups such as 3,5-dimethylpiperazin-l-yl, 3.3-diethylpiperazin-l-yl, 3,3,4,4-tetramethvlpvrrol-idinvl. 3-chloro-2-dioxanyl, and 3.5-dihydroxymorpholino. These can also bear a keto aroup, for instance, 3-ketopiperidyl.
The term "cancer" includes. but is not limited to, the following tumor types: breast, ovary, cervix, prostate. testis. esophagus, glioblastoma, neuroblastoma, stomach. skin, keratoacanthoma, lung, epidermoid carcinoma, large cell carcinoma, adenocarcinoma, bone, colon. adenoma, pancreas. thvroid, follicular carcinoma, undifferentiated carcinoma, papillary carcinoma, seminoma, melanoma, sarcoma, bladder carcinoma, liver carcinoma and biliary passages, kidney carcinoma, mveloid disorders, lvmphoid disorders. Hodgkin's. hairy cell carcinoma, cancer of the buccal cavity and pharynx (oral), lip, tongue. mouth, pharynx, small intestine. colon, rectum, large intestine, brain and central nervous svstem; and leukemia.
The compounds of Formulas I to VI can exist as pharmaceutically acceptable salts. esters. amides. and prodrugs. The term "pharmaceutically acceptable salts. esters. amides. and prodrugs- as used herein refers to those carboxvlate salts. amino acid addition salts, esters. amides. and prodrugs of the compounds of the present invention which are. within the scope of sound medical judgment. suitable for use in contact with the tissues of patients -t=ithout undue ~ toxicity. in:itation. allergic response, and the like, commensurate with a reasonable benefiv'risk ratio. and effective for their intended use, as well as the nN=itterionic forms. -;,here possible. of the compounds of the invention. The term "salts"
refers to the relatively nontoxic, inorganic, and organic acid addition salts and base salts of compounds of the above formulas. These salts can be prepared in situ durina the final isolation and purification of the compounds. or by separately reacting the purified compound in its free base form, for example. with a suitable organic or inorganic acid. and isolating the salt thus formed. Representative salts include the hydrobromide, hydrochloride, sulfate, bisulfate. nitrate, acetate. oxalate, valerate, oleate, palmitate, stearate. laurate. borate. benzoate, lactate, phdsphate.
tosylate, citrate, maleate, fumarate. succinate, tartrate. naphthylate mesylate, glucoheptonate, lactobionate, and laurylsulphonate salts, and the like. When the compound of the above formulas has one or more acidic groups. it can form a salt by reaction with a base. These salts may include cations based on the alkali and alkaline earth metals. such as sodium. lithium, potassium. calcium. magnesium, and the like. as well as inorganic bases such as amnionium. quaternary ammonium. and other amine cations includine. tetrameth~Ylammonium.
tetraethylammonium. methylamine, dimethylamine. trimethylamine.
triethylamine. ethylamine, and the like. Pharmaceutically acceptable salts are well-I:nown to those skilled in the art of medicinal chemistry. (See, for example, Berge S.M. et al.. "Pharmaceutical Salts." J. Pharm. Sci.. 1977:66:1-19).
Examples of pharmaceutically acceptable. nontoxic esters of the compounds of this invention include C 1-C6 alkvl esters. wherein the alkvl group is a straicht or branched hydrocarbon. substituted or unsubstituted. Esters also include C5-C7 cvcloalkvl esters. as well as arylalkyl esters such as benzvl and triphetn=lmethyl. C I-C4 Alkyl esters are preferred. such as methyl. ethvl.
2?.%trichloroeth~~l, and tert-but~=l. Esters of the compounds of the present invention may be prepared according to conventional methods, for example by reaction of an acid with an alcohol.
Examples of pharmaceutically acceptable amides of the compounds of this invention include amides derived from ammonia. primary C I-C6 alkNl amines and secondary C I-C6 dialkyl amines. wherein the alkyl groups are straiaht or branched. In the case of secondary amines. the amine may also be in the form of a i- or 6-membered heterocycle containing I nitrogen atom. Amides derived from ammonia. C 1-C; alkyl primarv amines. and C I -C-) dialkvl secondary amines are preferred. Amides of the compounds of the invention may be prepared according to conventional methods well-known to the medicinal chemists.
The term "prodrug" refers to compounds that are rapidly transformed in vivo to yield the parent compound of the above formulae, for example, by hvdrolysis in blood or stomach fluids. A thorough discussion of prodrugs is provided bx= Higuchi T. and Stella V.. "Pro-drugs as Novel Delivery Systems."
Vol.
14 of the A.C.S. Symposium Series. and in Biorei-ersible Carriers in Drug Design. ed. Edward B. Roche. American Pharmaceutical Association and Perzamon Press. 1987.
Representative compounds of the invention are sho%vn below in Table I.

Table I

NI NI f F
i i HN NH H7~; NH HN N N H

HN' p FfNp \ I \ I \ I
ci N ~ N
.~ .~
N
H H H

N N \ \ N \ \
I i i HNN NH ~ I N NH HN N NH
. O HN p HN O
I I
\ I \ ~ \ ci N N
H p~\ p~

\ \ F
N \ \ ?~ \ \
HN~ NH H.N)NH HN N N NH
HN O HN
HN O " k O
\ I \ 1 \ /(\
N
N CN,) C) N
.
~ ~
H
O p~/\
7 g 9 WO 01/55147 PCT/IBOl/00069 Table 1 (cont'd) F
Tr \ \ N \ \
I r \ \
HN NH HN NH
HN N N

CI I / I HN ---O
N N

H H N

, F
N N r ~ i i I i i 11N~ NH HN Iv' NH HN NH

HN 'O HNO H'''O
\ \ I \

N N N
' N

N N N
r N NI-{ HN N N NH IINN NH

\
6 \ I \
CI
N) N OH N) OH
C
, H
~ N
H

Table 1 (cont'd) F N
N \ \ N \ \
HN N N NH
NH I--I-NI N N NH
HN O
HN O tIN O
\ \ I
OH
N OH OH
.~
N

NI N F
I N \ \
ITN Nr~ N H FIN~i i N H ~ i HN N NH
HN O HN O
( I / I HN O
Cl N OH CN) OH
C ~ N OH
~
N N

F
N \ \ \ \ N \ \
i ~
HNN N H HN N/ N/ H 1iNNN H
HN O HN O HNO
cl N
N
C) ~
N N N

Table 1 (cont'd) INH N Nr N~ i ~~~~ T HN N N NH

HNT'N NH HN---O HNO
H-'; p ci N CN) CN~ N N, H 28 O i9 O~ 30 N F N \

HN N NH HN Ni N~
NH
HN N N H
HN O [ rn; p I I I ~ HN O
CN) ~N N
~
~ N
p 31 O 32 33 N
II / ~ N \ \ ~
J N
HN\N N NH HN NH HN N N H
N N ~
HN ~ O / HN O 11~1 \ / I HN O

N N

Table I (cont'd) Nr F N F
! \ \ N\ F
,~
HT~ N N ~ HN N N NH HN N N ~
HN O ~ O HNI O

F
N r N
,~

Ht''N N/ NH HNN N NH
~ HN N N NH ~
~
HN O O HN O
N N N
OH

N~ I \
NI N
~
HN N Ni NH
HN N N ~ HN N N ~

\ I HN O H1v O CN J O
N
N N
OH CH, 43 44 ~N) N H = 3 HC1 ~
N N~ \
~ I
HN N N NH2 HI~T N N I~T-CH, C=0 I
NH

CN) _(N),.
N CH, CH0 C 0+

CO.,Et NT N \ \ ~
HN \N N IT-CH~CH, HN N N j'TH2 C=0 \
NH
= 3 HCl 1~T N
N N
H IC-O+

0 CHNH'?
~T ~ \ NHCCH ~ ~ SO,CH, ~

TJ~T N NH ~Iv T I
~ N HN N NH
CHICH2 NH~ ~ -O CI ~ =S
CH, NH-1 Br C=0 I
N
CHI CH, NO-, CN O

~T SCH3 N i -OCH;
OCH.3 HN N N NH H N N ~'T NH , N i =0 CH3 SO~CH2OCHI

~
N = TFA

N
H

Representative compounds of the present invention, ,vhich are encompassed bv Formula I. include, but are not limited to. the compounds in Table 1 and their pharmaceutically acceptable acid or base addition salts, ester or amide analoas, and prodrugs thereof.
The compounds of the present invention can exist in unsolvated forms as well as solvated forms. includin2 hvdrated forms. In general. the solvated forms, including hydrated forms, are equivalent to unsolvated forms and are intended to be encompassed within the scope of the present invention.
Some of the compounds of Formula I have one or more chiral centers, and can thus exist as individual stereoisomers and mixtures thereof. Other compounds can exist in more than one aeometric form. This invention includes all optical and tzeometric isomers and forms. and mixtures thereof. Racemic mixtures of invention compounds are readily resolved into individual isomers by routine methods such as chromatography. fractional crvstallization. and classical resolution using opticallv active acids and salts. The individual isomers can also be prepared by chiral svnthesis. including chiral hvdrogenations and the like using commerciallv available chiral catalysts.
The compounds of the present invention are useful for treatins-i cancer (for example. leukemia. and cancer of the lung. breast, prostate. and skin such as melanoma) and other proliferative diseases, including. but not limited to, psoriasis. HSV. HIV, restenosis. and atherosclerosis. To utilize a compound of the present invention to treat cancer, a patient having cancer is administered a therapeutically effective amount of a pharmaceutically acceptable composition comprising an invention compound.
A further embodiment of this invention is a method of treating patients sufferina from diseases caused by vascular smooth muscle cell proliferation.
Compounds within the scope of the present invention effectively inhibit vascular smooth muscle cell proliferation and migration. The method entails inhibiting vascular smooth muscle proliferation, and/or migration by administering an effective amount of a compound of Formulas I to VI to a subject in need of treatment. "Subject" and "patient". as used herein, is a mammal such as a human, but also includes horses, cattle, sheep. and companion animals such as do;s and cats.
The compounds of the present invention can be formulated and administered in a wide variety of oral and parenteral dosage forms, including transdermal and rectal administration. It will be recognized to those skilled in the art that the following dosage forms may comprise as the active component, either a compound of Formula I or a corresponding pharmaceutically acceptable salt or solvate of a compound of Formula I.
A further embodiment of this invention is a pharmaceutical composition comprising a compound of Formulas I to VI together with a pharmaceutically acceptable carrier. diluent. or excipient therefor. For preparing pharmaceutical compositions with the compounds of the present invention.
pharmaceuticallyacceptable carriers can be either a solid or liquid. Solid form preparations include powders, tablets, pills, capsules. cachets. suppositories. and dispensable granules.
A solid carrier can be one or more substances which may also act as diluents, flavoring agents, binders, preservatives. tablet disintegrating agents, or an encapsulating material.
In powders. the carrier is a finely divided solid such as talc or starch which is in a mixture with the finely divided active component. In tablets, the active component is mixed with the carrier having the necessarv binding properties in suitable proportions and compacted in the shape and size desired.
The formulations of this invention preferably contain from about 5% to about 70% or more of the active compound. Suitable carriers include ma(inesium carbonate. magnesium stearate, talc. suLar. lactose. pectin. dextrin. starch, gelatin.

tragacanth, methvlcellulose, sodium carboxvmethvlcellulose. a low melting wax, cocoa butter, and the like. A preferred form for oral use are capsules. which include the formulation of the active compound with encapsulating material as a carrier providing a capsule in which the active component with or without other carriers. is surrounded by a carrier, which is thus in association with it.
Similarly.
cachets and lozenges are included. Tablets, powders, capsules, pills. cachets.
and lozenges can be used as solid dosage forms suitable for oral administration.
For preparing suppositories. a low melting wax, such as a mixture of fatty acid glycerides or cocoa butter. is first melted, and the active component is dispersed homogeneously therein. as by stirring. The molten homoaenous mixture is then poured into convenient size molds. allowed to cool, and thereby to solidify.
Liquid form preparations include solutions, suspensions, and emulsions such as water or water/propylene glycol solutions. For parenteral injection, liquid preparations can be formulated in solution in aqueous polyethylene glycol solution, isotonic saline, 5% aqueous glucose, and the like. Aqueous solutions suitable for oral use can be prepared by dissolving the active component in water and adding suitable colorants. flavors, stabilizing and thickening agents as desired.
Aqueous suspensions suitable for oral use can be made by dispersing the finely divided active component in water and mixina with a viscous material. such as natural or synthetic gums. resins, methvlcellulose. sodium carboxvmethylcellulose. or other well-known suspending agents.
Also included are solid form preparations that are intended to be converted, shortly before use. to liquid form preparations for oral administration.
Such liquid forms include solutions, suspensions, and emulsions. These preparations may contain, in addition to the active component. colorants, flavors, stabilizers. buffers, artificial and natural sweeteners, dispersants, thickeners, solubilizing aaents, and the like. Vvaxes, polymers, microparticles, and the like can be utilized to prepare sustained-release dosage forms. Also, osmotic pumps can be employed to deliver the active compound uniformly over a prolonged period.
The pharmaceutical preparations of the invention are preferably in unit dosage form. In such form. the preparation is subdivided into unit doses containing appropriate quantities of the active component. The unit dosage form can be a packaged preparation. the package containing discrete quantities of preparation, such as packeted tablets, capsules, and powders in vials or ampules.
Also. the unit dosage form can be a capsule. tablet, cachet. or lozenge itself. or it can be the appropriate number of any of these in packaged form.
The therapeutically effective dose of a compound of Formula I will generally be from about 1 to about 100 mg/kg of body weight per day. Typical adult doses will be about 50 to about 800 mg per day. The quantity of active component in a unit dose preparation may be varied or adjusted from about 0.1 to about 500 ma, preferably about 0.5 to 100 mg according to the particular application and the potencv of the active component. The composition can, if desired, also contain other compatible therapeutic agents. A subject in need of treatment with a compound of Formula I is administered a dosage of about 1 to about 500 mg per day. either singly or in multiple doses over a 24-hour period.
The compounds of the present invention are capable of binding to and inhibiting the activity of proteins having the ability to phosphorvlate other proteins, such as cdks, PDGFr. FGFr, c-Src, and EGFr. Cdks form complexes with cyclins, and these complexes phosphorylate key proteins allowing cells to proceed through the cell cycle (Meijer L., Progress in Cell Cvcle Research, 1995:1:35 1-363). The compounds of this invention inhibit this phosphorylation and therefore can be used as anti-proliferative agents for the treatment of cancer and/or restenosis and other proliferative diseases.
Because of their inhibitory activitv against cdks and other kinases, the compounds of the present invention are also useful research tools for studving the mechanism of action of those kinases, both in vitro and in vivo.
The preparation and use of the compounds of this invention are further described in the followinQ detailed example. The examples are intended to illustrate particular embodiments of the invention, and are not intended to limit the scope of the specification or the claims in anv way. The invention compounds are prepared by svnthetic methodologies well-known to those skilled in the art of or2anic chemistnT, and utilize commercially available starting materials and reaaents.
It may be desirable during the synthesis of an invention compound to derivatize reactive functional groups in the molecule undergoing reaction so as to avoid unwanted side reactions. Functional groups such as hydroxy, amino, and acid groups typically are protected with suitable groups that can be readily removed when desired. Use of common protecting groups is described fullv by Green and Wuts in Protective Groups in Organic Svnthesis, John Wiley and Sons.
New York. Ne~~- York (?"d Edition. 1991). Typical hvdroxv protecting groups include ether forming groups such as benzvl, and aryl groups such as tert-butoxvcarbonyl (Boc). formvl, and acetv1. Amino protecting groups include benzvl, arvl such as acetvl, and trialkvlsilvl groups. Carboxylic acid groups typically are protected by conversion to an ester that can be easilv hydrolyzed, for example. trichloroethyl, tert-butyl. benzyl, and the like.
As noted above. some of the invention compounds have one or more chiral centers. and thus can exist as individual optical isomers and geometric isomers, and mixtures thereof. Compound 106, for example. has two asvmmetric centers, and has the cis configuration. This invention includes all such geometric isomers, enantiomers and RS racemates. as well as the individual R or S isomers of chiral compounds. All individual isomers and mixtures thereof are included in this invention. Individual isomers are readily prepared by a chiral synthesis, or by conventional resolution techniques well-known to those skilled in the art.
An illustration of the preparation of compounds of the present invention is shown in Schemes 1-4. The synthesis of Compound 1(Example 15) is depicted in Scheme 1: however, it should be recognized that the general scheme is applicable to all of the invention compounds. Each step shown in the Schemes is further illustrated in the detailed examples that follow.
In Scheme 1. a 2-methvlthio-4-halo-5 -alkoxvcarbonvlpvrimidine is reacted with ammonium hydroxide to give the correspondino 4-amino derivative. The ester is reduced by reaction by reaction with LiAI H4 to give the 5-hvdroxvmethvl analog. which in turn is oxidized to a 5-formyl derivative.
The 5-formvl group is converted to an unsaturated (acrvlate) group, which is cvclized to form a pvrido[2.3-d]pvrimidine. The pvridopvrimidine is converted to a key intermediate. namelv 2-methvlsulfanyl-pvrido[2.3-d]pvrimidine-7-vlamine, which is readilv oxidized to 2ive a?-methvlsulfinvl analog. The 2-methvlsulfinyl group is easily displaced bv reaction with an amine R-)NH-) to provide the invention _2 5_ compounds of Formula I. The 7-amino group on the pyridopyrimidine ring is readily converted to a urea by reaction with an isocyanate such as R19 N=C=O.

Scheme 1 O O

N O~\ a N b N OH
o I I ~

c N H d N\ O/\ e ~ ---~ ~ ---~
--~ i i NH-, N
I NH

N \ \ 1;
~ f S,~ O S-N N C1 S N NH, H

N

, N \ \ i / j i NH-, CN) N
I
Boc N N

HN N 'H -~ HN IN H
HN11~1O HN'I-~IO
\ I \ I

(ND CN) N N
I H
Boc The reactants shoAn in Scheme I have the following meanings:
(a) NH3; (b) LAH; (c) Mn02; (d) Ph3PCHCO2Et; (e) DBU: (f) POC13; (g) NH-:
(h) ( )-Trans-2-(phenylsulfonyl)-3-phenyloxaziridine; (i) 4-(4-Boc-piperidine)aniline; (j) NaH, t-Butvlisocyanate; (k) HC1 Scheme 2 illustrates an alternative synthesis of pyridopyrimidine having a urea functionality at the 7-position. Whereas such ureas were prepared in Scheme I by reaction of an isocyanate with a 7-amino-pyridopyrimidine, Scheme 2 utilizes carbonvldiimidazole to provide an intermediate imidazolide.
The imidazolide readilv reacts with an amine R19NH2 to give the correspondina urea. Scheme 2 illustrates this process by showing the synthesis of Compound 51, and is more fully described in Example 3 2.

Scheme 2 N \ \ ~i \ \

H1~ / N H, a 1 IT~ H b_c NN O
\ \ ~
CN) N
N
Boc Boc r HN H
HN O
N

Conditions: (a) NaH. CarbonvIdiimidazole: (b) Cvclopentvlamine; (c) HCI
Compounds of Formula 1 may also be prepared according to Scheme 3, ~ wherein the svnthesis of compound 4 (Example 45) is depicted. 4-Amino-2-methanesulfanyl-pyrimidine-5 -carboxaldehy de is reacted with methyl magnesium bromide to 2ive the corresponding -~-(2-h},droxveth),l)-pyrimidine. The alcohol is oxidized to give the methyl ketone analoii. The methyl ketone is reacted with diethvl cyanomethvl phosphonate and cvclized to a5-methvl-7-amino-pyridopvrimidine. Further reaction as in Schemes I or 2 gives invention compounds such as compound 4.

Scheme O

?''I \ H a N OH b N O
S NH,~
NH-2 S~'J~N NH-2 ~ ~ I I

N
asin HN ' ' NH
c N\ Scheme I or 2_ HN' O
i N NH2 CN) N

Conditions: (a) MeMgBr; (b) MnO-): (c) (EtO)2P(O)CH-)CN

Compounds of Formula I may also be prepared according to Scheme 4, ~ -,,vherein the svnthesis of compound 12 (Example 40) is depicted. In this scheme, the ?-methvlthio group of a pyrimidine is first oxidized to the corresponding methvlsulfinyl analog. The methylsulfinyl group is displaced by reaction with an amine R2NH-). The 5-carboxaldehvde is then derivatized as in Scheme 1 and cvclized to give the corresponding 2-(R2NH) substituted 7-amino pyridopvrimidine. The 7-amino uroup is arvlated or otherwise derivatized as illustrated in Schemes 1-3.

Scheme 4 1\ ~ O
N O a N O b IfN NH, I --~ --~
S NH, O"NH, Boc N N i i c HN NH, Scheme I or ? HN H
r HN O
N

Boc Conditions: (a) ( )-Trans-2-(phenylsulfonyl)-3-phenyloxaziridine: (b) 4-(4-Boc-piperidine)-aniline: (c) (EtO)2P(O)CH-)CN

Any of the invention compounds of Formulas 1-VI mav be prepared according to Schemes 1-4. wherein the synthesis of compounds 1. 51. 4. and 12.
respectively, are illustrated. Those having skill in the art of organic chemistry will recognize that the startina materials may be varied. and additional steps may be employed to produce compounds encompassed bv the present invention, as demonstrated by the following specific examples.

-30a-Examples of compounds falling within the scope of the present invention include:

1-tert-Butyl-3-(2-phenylamino-pyrido[2,3-d]pyrimidin-7-yl)-urea;

1-tert-Butyl-3-[2-(4-fluoro-3-methyl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(4-Chloro-phenyl)-3-[2-(4-fluoro-3-methyl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Isopropyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-tert-Butyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-Cyclohexyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;

1-Cyclopentyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimdin-7-yl]-urea;
1-Cyclohexyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-Cyclopentyl-3-[5-methyl-2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimdin-7-yl]-urea;
1-Cyclohexyl-3-[6-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[6-bromo-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-Cyclohexyl-3-[6-cyano-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

-30b-1-Cyclohexyl-3-[6-chloro-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[6-fluoro-5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-Cyclohexyl-3-[6-bromo-5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[6-chloro-5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Isopropyl-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Ethyl-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-[5-Methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-Methyl-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-l-methyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(4-Hydroxy-cyclohexyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(4-Amino-cyclohexyl)-3-[2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(2-Dimethylamino-ethyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-(3-Morpholino-4-yl-propyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

-30c-3-Cyclohexyl-l-methyl-l-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
N,N-Dimethyl-N'-[5-methyl-2-[[4-(1-piperazinyl)phenyl]-amino]-pyrido[2,3-d]pyrimidin-7-yl]-sulfamide;

1-Cyclohexyl-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-thiourea;
N-[2-(4-Piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-acetamide;

4-[7-(3-Cyclohexyl-ureido)-pyrido[2,3-d]pyrimidin-2-ylamino]-benzenesulfonamide;

1-Cyclohexyl-3-{2-[4-(1-piperazin-1-yl-methanoyl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-Cyclohexyl-3-[2-(4-fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-(2-{4-[4-(2-Amino-4-methyl-pentanoyl)-piperazin-1-yl]-phenylamino}-pyrido[2,3-d]pyrimidin-7-yl)-3-cyclohexyl-urea;
1-(2-{4-[4-(2-Amino-3-methyl-butanoyl)-piperazin-1-yl]-phenylamino}-pyrido[2,3-d]pyrimidin-7-yl)-3-cyclohexyl-urea;
4-{4-[7-(3-tert-Butyl-ureido)-pyrido[2,3-d]pyrimidin-2-ylamino]-phenyl}-piperazine-l-carboxylic acid tert-butyl ester;

4-{4-[7-(3-Cyclohexyl-ureido)-pyrido[2,3-d]pyrimidin-2-ylamino]-phenyl}-piperazine-l-carboxylic acid tert-butyl ester;

1-(3-Hydroxy-propyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

-30d-1-((S)-1-Hydroxymethyl-3-methyl-butyl)-3-[2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
4-Methyl-piperazine-l-carboxylic acid [2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-amide;

Morpholine-4-carboxylic acid [2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-amide;
3-[2-(4-Piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-1,1-dipropyl urea;

Piperazine-l-carboxylic acid[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-amide;
1-((R)-1-Hydroxymethyl-2-methyl-propyl)-3-[2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1,1-Bis-(2-hydroxy-ethyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-[6-Bromo-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-tert-butyl-urea;
1-[6-Bromo-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-methyl-urea;
1-{6-Bromo-2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-tert-butyl-urea;
1-{6-Bromo-2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-cyclohexyl-urea;
1-[2-(4-Fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-(3-morpholin-4-yl-propyl)-urea;

1-[2-(4-Fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-(2-hydroxy-ethyl)-urea;

-30e-1-(2-Amino-ethyl)-3-[2-(4-fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(2-Dimethylamino-ethyl)-3-[2-(4-fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-Cyclohexyl-3-{2-[4-(3,3-dimethyl-piperazin-l-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-tert-Butyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-(3-morpholin-4-yl-propyl)-urea;

1-tert-Butyl-3-{6-chloro-2-[4-(cis-3,5-dimethyl-piperazin-l-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;
3-Cyclohexyl-l-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-1-methyl-urea;
3-Cyclohexyl-l-ethyl-l-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
3-tert-Butyl-l-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-l-ethyl-urea;

1-[5-Methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-propyl-urea;
7-(3-tert-Butyl-ureido)-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidine-6-carboxylic acid ethyl ester;
1-[6-Fluoro-5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-isopropyl-urea;
1-Cyclohexyl-3-{2-[4-(3,3-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;

-30f-1-Cyclohexyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-methyl-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-tert-Butyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-methyl-pyrido[2,3-d]pyrimidin-7-yl}-urea;

1-tert-Butyl-3-[6-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-{2-[4-(cis-3,5-Dimethyl-piperazin-1-yl)-phenylamino]-6-methyl-pyrido[2,3-d]pyrimidin-7-yl}-3-isopropyl-urea;
1-Cyclopropyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-methyl-pyrido[2,3-d]pyrimidin-7-yl}-urea; and 1-tert-Butyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-ethyl-pyrido[2,3-d]pyrimidin-7-yl}-urea.

The invention is illustrated further by the following detailed examples which are not to be construed as limiting the invention in scope or spirit to the specific procedures described in them. The starting materials and various intermediates may be obtained from commercial sources, prepared from commercially available organic compounds, or prepared using well-known synthetic methods.

4-Amino-2-methanesulfanylp,rimidine-5-carboxy/ic acid ethYl ester To a room temperature solution of 4-chloro-2-methanesulfanvl-pyrimidine-5-carboxvlic acid ethyl ester (15.0 g, 65 mmol) in 200 mL of tetrahvdrofuran is added 25 mL of triethylamine followed bv 35 mL of aqueous ammonium hydroxide. After stirring at room temperature for 1.5 hours, an additional 30 mL of aqueous ammonium hydroxide is added. and stirring is continued for 1 hour. The reaction mixture is concentrated in vacuo and partitioned between ethyl acetate and saturated aqueous sodium bicarbonate.
The organic laver is washed with brine. dried over magnesium sulfate, filtered, and concentrated in vacuo. Ethyl acetate and hexane are added, and the resultant solid is collected by filtration to provide 10.84 g (79%) of 4-amino-2-methanesulfanyl-pyrimidine-5-carboxvlic acid ethvl ester.

(4-Anzino-2-methanesulfanti7! pyrimidiur-5-t,!)-methano!
A solution of 4-amino-2-methanesulfanvl-pyrimidine-5-carboxvlic acid ethyl ester (13.36 g, 63 mmol) in 250 mL of tetrahvdrofuran is added dropwise to a room temperature suspension of lithium aluminum hydride (3.82 g. 100 mmol) in 250 mL of tetrahvdrofuran. After 30 minutes. the reaction is cooled to 0 C, and isopropyl alcohol is added until bubbling diminishes. The reaction is quenched with 15 mL of water. 15 mL of 15% NaOH, and 50 mL of water. and the mixture is stirred for 1 hour. The white precipitate is removed by filtration and washed with ethyl acetate. The filtrate is concentrated in vacuo and 3:1 hexane:ethyl acetate is added. The solids are collected, washed with 3: ] hexane:ethyl acetate, followed bv hexane. The solid is dissolved in ethyl acetate, and the solution is dried over magnesium sulfate. Filtration followed by concentration in vacuo gives 8.14 g (76%) of (4-amino-2-methanesulfanvl-pvrimidin-5-vl)-methanol.

Analysis calculated for C6H9N3OS:
C. 42.09: H. 5.30; N. 24.54.
Found: C. 42.31: H. 5.24; N, 24.27.

4-Afnino-2-methanesulfany,lp=rimidine-S-carboxaldeh_yde To (4-amino-2-methanesulfanyl-pvrimidin-5-vl)-methanol (8.14 g.
48 mmol) in 1 L of chloroform is added manEianese oxide (33.13 ~. 381 mmol).
The suspension is stirred at rooni temperature overnight then filtered through celite and Nvashed with 300 mL of chloroform. The filtrate is concentrated in vacuo to give 8.14 g (quantitative yield) of 4-amino-2-methanesulfanvl-pvrimidine-5-carboxaldehvde, mp 185-187 C. Literature mp = 183-184 C, JOC, 1958:23:1738.
Analvsis calculated for C6H7N3OS:
C. 42.59; H. 4.17: N. 24.83.
Found: C. 42.84: H, 4.21: N. 24.73.

Ethy13-(4 Amiizo-2-methanesulfaiiylp,rirnidin-5-y1)acrvlate To a room temperature solution of 4-amino-2-methanesulfanvl-pvrimidine-5-carboxaldevde (4.08 g. 24.14 mmol) in 100 mL of tetrahydrofuran is added (carbethoxvmethylene) triphenvlphosphorane (10.80 31 mmol). The reaction mixture is heated at reflux for 3 hours then stirred at room temperature overnight.
The reaction mixture is concentrated in vacuo, and the residue is purified by flash chromatography. eluting with 1:1 ethyl acetate:hexane. to provide 4.30 g (75%) of ethyl 3-(4-amino-2-methanesulfanv l-pvrimidin-5-vl )acrvlate: mp softens at 108 C.
Analvsis calculated for C 1 pH 1;N ;O~S:
C. 50.19: H. 5.48: N. 17.56.
Found: C. 50.22: H. 5.45: N. 17.24.

2-Methanesulfanhl-8H-pvrido[2,3-dJpvrimidin- 7-one To a room temperature solution of ethyl 3-(4-amino-2-methanesulfanvl pvrimidin-5-vl)acrvlate (368 mg, 1.53 mmol) in 3 mL of N.N-diisopropylethylamine is added 380 L of 1,8-diazabicvclo[5.4.0]undec-7-ene.
The reaction mixture is heated at reflux for 3 hours then cooled to room temperature and concentrated. The residue is purified by flash chromatography eluting v6th ethvl acetate. The fractions containinci the product are partiallv concentrated in vacuo, and the solids are removed bv filtration to provide 134 ma (45%) of 2-methanesulfanvl-BH-pyrido[2.3-d]pvrimidin-7-one. mp 269-271 C.
Analvsis calculated for C8H7N3OS:

C. 49.73. H. 3.65 : N. 21.75.
Found: C. 49.67: H. 3.46: N. 21.49.

7-C/rloro-2-ntethvlsulfanyl pvrido[2,3-dJpvrintidine A suspension of 1.0 cy (5.2 mmol) of 2-methvlsulfanvl-8H-pvrido[2.3-d]pyrimidin-7-one (Example 5) in 10 mL of phosphorus oxvchloride is heated under reflux for 1 hour. The resultina solution is cooled and concentrated to 2ive a solid. which is triturated with cold water and filtered to aive 1.05 g of crude product. Recrvstallization from acetonitrile gives 0.76 g(69 ro) of the product. mp 201-203 C.
MS (APCI) M+1: Calcd 212.0; Found 212Ø
Anal. Calcd for C8H6C1 I S I N3:

C. 45.3 9: H. 2.86: N. 19.85.
Found: C. 45.53: H. 2.90: N. 19.74.

2-Meth hlsttlfan t,lp,rido[2,3-d]pti=rimiditt- 7-vlantine A suspension of 2.95 g(13.9 mmol) of 7-chloro-2-methvlsulfanvl-pvrido[2.3-d]pvrimidine (Example 6) in 200 mL of isopropanol saturated with ammonia is sealed and heated at 40 C for 65 hours. The suspension is resaturated with ammonia and heated for another 18 hours at 40 C. The solid is collected bv filtration and triturated with water to give 1.98 g (74.2%) of the product, mp >250 C.
MS (APCI) M+l : Calcd 193.1: Found 193Ø
Anal. Calcd for C8H8N4S I:

C. 49.98; H. 4.19: N. 29.14.
Found: C, 50.14: H. 4.22: N, 29.04.

2-Nfetltanesuljrnti,! pti,rido[2,3-dJpt'rintidin-7-ylantine A suspension of 10.63 g (55.3 mmol) of 2-methylsulfanvl-pvrido[2,3-d]pvrimidin-7-ylamine (Example 7) in 300 mL of dichloromethane and 300 mL of methanol is treated with 18.06 g (69.1 mmol) of ( )-trans-2-(phenvlsulfonyl)-3-phenyloxaziri dine and stirred overnight. The suspension is filtered to remove a small amount of solid. concentrated to approximately 25 mL, and diluted with ethvl acetate. The solid is collected by filtration to give 9.27 g (80.5%) of the product. mp 180 C (dec).
MS (APCI) M+1: Calcd 209.0; Found 209.1.

N2-Plienv! pti,rido[2,3-dJpt'rintidine-2, 7-diantine A suspension of 0.44 - (2.1 mmol) of 2-methanesulfinvl-pvrido[2.3-d]pyrimidin-7-ylamine (Example 8) and 0.39 mL (4.2 mmol) of aniline in 2 mL of dimethylsulfoxide is heated at 100 C overnight. The resulting solution is cooled and poured into water. Ethyl acetate is added to the suspension. and the solid is collected by filtration. The solid is purified by flash chromatography.
eluting with gradient of 0% to 20% methanol/dichloromethane durino 30 minutes to give 0.14 g(29%) of the product. mp 255-260 C.

MS (APCI) M+1: Calcd 238.1: Found 238.1.
Anal. Calcd for CI - HI IN5=0.18 H20:

C. 64.92: H, 4.76: N. 29.12.
Found: C. 65.26: H. 4.75: N. 28.76.

1-tert-Butv1-3-(2 phenvlamino pyrido[2,3-dJpvrimidin-7 yl)-urea To a solution of 0.1022 g (0.431 mmol) of N2-phenyl-pvrido[2.3-d]pyrimidine-2,7-diamine (Example 9) in 2 mL of dimethvlformamide. cooled in an ice bath, is added 0.019 g (0.47 mmol) of 60% sodium hydride. The resulting solution, cooled in an ice bath. is then treated with 0.054 mL (0.47 mmol) of tert-butyl isocyanate. The solution is stirred cold for 15 minutes. then at room temperature for 1 hour. The solution is poured into ice-water to give a solid which is collected bv filtration and washed with hexane to give 0.0849 g (57.8%) of the product (compound 45), mp 227 C (dec).
MS (APCI) M+1: Calcd 337.2; Found 337.1.
Anal. Calcd for C 1 8H2ON6O1 =0.27 H20:

C, 63.35; H. 6.07; N, 24.63.
Found: C. 63.73: H. 5.82: N. 24.20.

4-(4-Nitrophenyl) piperazine-l-carboxvlic acid tert-butvl ester A suspension of 7.5 g(36 mmol) of 1-(4-nitrophenvl)-piperazine and 6.94 mL (40 mmol) of ethyl-diisopropyl-amine in 75 mL of dichloromethane is treated with 8.69 g (40 mmol) of di-tert-butyl dicarbonate and stirred at room temperature overnight. The resulting solution is washed with saturated aqueous sodium bicarbonate, then with water, dried (magnesium sulfate), and concentrated.
The resulting material is purified by flash chromatography eluting with a gradient of 10% to 30% ethyl acetate/hexane during 10 minutes to give 8.62 g (77.5%) of the product, mp 136-140 C.
MS (APCI) M+l: Calcd 308.2: Found 308.2.

4-(4-Antino p/renvl) piperazine-l-carboxylic acid tert-butyl ester To a suspension of 1.46 g (4.8 mmol) of 4-(4-nitrophenvl)-piperazine-1-carboxvlic acid tert-butvl ester (Example 11) and I g of Raney Nickel in 50 mL
of tetrahvdrofuran is added hvdroaen to an initial pressure of 54.5 psi. The reaction is shaken for 14 hours and then filtered. The filtrate is concentrated to give 1.29 g (97%) of the product as a solid.
MS (APCI) M+1: Calcd 278.2; Found 278.2.
Anal. Calcd for C15H23N302:

C. 64.96: H. 8.36: N. 15.15.
Found: C. 65.22: H. 8.58: N, 14.58.

4-14-(7-Amino pvrido[2,3-dJp1'rimidin-2-i,lamino) pheiit'IJ-piperazine-1-carboxi=lic acid tert-butyl ester Bv substitutin~ 4-(4-amino-phen),l)-piperazine-I-carboxvlic acid tert-butyl ester (Example 12) for aniline in Example 9. 0.0744 g(36.0%) of the product is obtained. mp 219-220 C.
MS (APCI) M +1: Calcd 422.2; Found 422.2.
Anal. Calcd for C22H-27N7O2-0.5 H20:

C. 61.38: H, 6.56: N. 22.77.
Found: C. 61.34: H, 6.30: N. 22.47.

4-{4 -17-(3-tert-Butyl-ureido) pti,rido/2,3-d]phrintidin-2-ti'laminoJ-phenv!}-piperazine-1-carbo.zylic acid tert-butl,/ ester Bv substitutina 4-[4-(7-amino-pyrido[2.3-d]pyrimidin-2-ylamino)-phenyl]-piperazine-l-carboxvlic acid tert-butyl ester (Example 13) for N2-phenyl-pyrido[2.3-d]pyrimidine-2.7-diamine in Example 10, 0.3354 g12 (67.9%) of the product (compound 79) is obtained, mp 225 C (dec).
MS (APCI) M+l: Calcd 521.3; Found 521.2.
Anal. Calcd for C.27H36N803:

C. 62.29: H. 6.97: N. 21.52.
Found: C. 62.33: H. 6.81: N. 21.43.

1-tert-Butvl-3-[2-(4 piperazin-1 yl-phenylannino) pyrido[2,3-dJpt'rin:idin-7-t'1J-urea To a suspension of 0.100 g(0.192 mmol) of 4-{4-[7-(3-tert-butvl-ureido)-pvrido[2.3-d]pyrimidin-2-v lamino]-pheny l}-piperazine-l-carboxy lic acid tert-butvl ester (Example 14) in 2 mL of methanol is added 2 mL of 4 M hydrogen chloride/dioxane to give a solution. The suspension is stirred at room temperature overnisiht, then diluted with diethyl ether. The material is collected by filtration to give 0.0941 - (93.4%) of the product (compound 1). mp 21 5 C (dec).

MS (APCI) M+l: Calcd 421.2; Found 421.1.

Anal. Calcd for C-)H-)gNgO1 -2.10 HC1. 1.51 H-)O:
C. 50.40: H. 6.37: N. 21.37; Cl (total). 14.20.
Found: C. 50.40: H. 6.18: N. 21.03: Cl (total), 14.33.

4-{4-[7-3-Cvclohe.till-ureido) pt'rido[2,3-dJpt~rimidin-2-ylan:irnoJ-phenyl}-piperazine-1-carboxylic acid tert-butyl ester BN, substitutin2 cvclohexvl isoc-vanate for tert-butvl isocvanate in Example 14. 0.1463 g (70.4%) of the product (compound 80) is obtained, mp 241 C (dec).
MS (APCI) M-1: Calcd 547.3: Found -547.4.
Anal. Calcd for C-)9H38NgO;-0.28 H-)O:

C. 63. I 3: H. 7.04: N. 20. 31.
Found: C. 63.14: H. 6.81: N. 20.2 5.

1-C=clohe~:1,l-3-[2-(4 piperazhr-1-~=I-phent.lantino) phrido[2,3-dJpt~rin:idin-7-ylJ-urea Bv substituting 4-,4-[7-(3-c%,clohexvl-ureido)-ptirido[2.3-d]pyrimidin-2-vlamino]-phen,,l }-piperazine- l-carboxvlic acid tert-butyl ester (Example 16) for 4-{4-[7-(3-tert-butvl-ureido)-p~'rido[2.3-d]pvrimidin-2-vlamino]-phenvl}-piperazine-l-carboxylic acid tert-butyl ester in Example 15. 0.0871 g (81.4%) of the product (compound 9) is obtained, mp 200 C (dee).

MS (APCI) M+1: Calcd 447.3; Found 447.3.

Anal. Calcd for C24H30N8O 1=2.55 HC1=2.82 H2O:

C. 48.83; H. 6.52; N, 18.98; Cl (total), 15.31.
Found: C. 48.83: H, 6.18: N. 18.89; Cl (total). 15.37.

N2-(4-Fl uoro-3-meth ti,l-ph en yl) prido[2,3-d]phrimidine-2, 7-diamine Bv substitutinR 4-fluoro-3-methvlaniline for aniline in Example 9, 0.2025 g(392%) of the product is obtained as a solid.
MS (APCI) M + 1: Calcd 270.1; Found 270Ø

1-tert-Butvl-3-[2-(4 Jluoro-3-methl~l-phenylamino) pvrido[2,3-dJpyrimidin-7 y1]-urea By substituting N2-(4-fluoro-3-methvl-phenvl)-pyrido[2.3-d]pyrimidine-2.7-diamine (Example 18) for N2-phenvl-pvrido[2.3-d]pvrimidine-2.7-diamine in Example 10, 0.0656 g (47.9%) of the product (compound 46) is obtained, mp 230 C (dec).
MS (APCI) M+1: Calcd 369.2: Found 369.1.
Anal. Calcd for C I qH-) 1 F 1 N601:

C. 61.94: H. 5.75: N. 22.81.
Found: C. 61.82: H. 5.73: N. 22.75.

1-(4-Chloro phent'1)-3-[2-(4 fluoro-3-methl,l pheiiti,lan:irno)-phrido[2,3-dJpvr[ntidin-7-vIJ-ttrea Bv substituting 4-chlorophenvl isocvanate for tertiarv-butvl isocyanate in Example 19, 0.050 g (37%) of the product (compound 47) is obtained, mp >250 C.
MS (APCI) M+1: Calcd 423.1: Found 423.1.

Anal. Calcd for C,? IH16FIClIN601=0.23 H,)O:

C. 59.07; H. 3.89: N, 19.68.
Found: C. 59.09: H. 3.97: N. 19.65.

1-{2-[4-(4 Acetyl piperazin-1 yl) phenylaminoJ-pyrido[2,3-dJpyritnidin-7-y1}-3-tert-butyl-urea To a suspension of 0.145 g (0.277 mmol) of 1-tert-butyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2.3-d]pyrimidin-7-vl]-urea (Example 15) in 5 mL of dichloromethane is added 0.19 mL (l.l l mmol) of ethyl-diisopropyl-amine. The suspension is cooled in an ice bath and treated with 0.024 mL (0.33 mmol) of acetyl chloride. The suspension is stirred at room temperature overnight, then filtered. The solid is washed with dichloromethane. The filtrate and washinas are combined, washed with water, dried (magnesium sulfate), and concentrated. The material is purified by flash chromatography eluting with a gradient of 0% to 5%
methanol/dichloromethane during 30 minutes to give 0.0674 g (51.8%) of the product (compound 5). mp 206-208 C (dec).
MS (APCI) M+1: Calcd 463.3: Found 463.3.
Anal. Calcd for C24H30N8O-)=0.40 H-)O:

C. 61.36: H. 6.61: N. 23.85.
Found: C. 61.38: H. 6.37; N. 23.98.

4-{4-[7-(3-Isopropyl-ureido)-pyridol2,3-dJpyrimidiir-2 ylaminoJ-phenylJ-piperazine-l-carbo.xylic acid tert-butti=l ester By substituting isopropyl isocyanate for tert-butyl isocvanate in Example 14. 0.909 g(69.910) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 507.3: Found 507.4.

1-Isopropvl-3-[2-(4 piperazin-1-v1 plrenvlamino) pvrido[2,3-dJpvrimidiir-7-vIJ-urea By substituting 4-{4-[7-(3-isopropyl-ureido)-pyrido[2.3-d]pyrimidin-2-vlamino]-phenyl}-piperazine-l-carboxylic acid tert-butvl ester (Example 22) for 4-{4-[7-( -' 3 -tert-butyl-ureido)-pyrido[2,3-d]pyrimidin-2-vlamino]-phenyl }-piperazine- l -carboxylic acid tert-butyl ester in Example 15. 0.0287 g(27.9 /o) of the product (compound 48) is obtained, mp 190 C (dec).

MS (APCI) M+1: Calcd 407.2; Found 407.1.

Anal. Calcd for C-) 1 H26NgO1 =2.05 TFA-0.84 H-)O:
C. 46. 00: H. 4.57: N. 17.10.
Found: C. 46.00; H. 4.65: N. 17.09.

Cis-3,5-dimethvl-l-(4-nitro plrenv!) piperazine A suspension of 6.74 g (47.8 mmol) of 4-fluoro-nitro-benzene and 10.91 g (95.5 mmol) of cis-2,6-dimethyl-piperazine is heated at 45 C for 1 hour. The reaction mixture is cooled and shaken with dichloromethane and water. The organic laver is dried (maanesium sulfate) and concentrated to give 11.62 g (>100 /0) of the product as a solid.

Cis-2,6-dinrethyl-4-(4-nitro phent,!) piperazine-l-carbo.rti=lic acid tert-butyl ester By substitutinp cis-3.5-dimethvl-1-(4-nitro-phenyl)-piperazine (Example 24) for 1-(4-nitrophenyl)-piperazine in Example 11. 14.87 g (92.8%) of the product as a solid is obtained.

4-(4-Amino pheir1,/)-cis-2,6-dimethi,/-piperazine-l-carboxl,/ic acid tert-butyl ester Bv substitutin2 cis-2.6-dimethvl-4-(4-nitro-phenyl )-piperazine-1-carboxvlic acid tert-but~~l ester (Example 25) for 4-(4-nitro-phenyl)-piperazine-1-carboxvlic acid tert-butyl ester in Example 12. 5.03 g (64.7%) of the product as a solid is obtained.

4-[4-(7-Aminop,rido[2,3-d]pyrimidin-2ylamino) pheiiti,lJ-cis-2,6-dimetht'!-piperazine-1-carboxylic acid tert-butvl ester Bv substituting 4-(4-amino-phenyl)-cis-2.6-dimethyl-piperazine-1-carboxvlic acid tert-butvl ester (Example 26) for aniline in Example 9.
0.6463 g (59.8%) of the product is obtained, mp 245 C (dec).

MS (APCI) M+1: Calcd 450.3; Found 450.3.

4-{4-[7-(3-tert-Butyl-ureido) pvrido[2,3-d]pvrimidin-2 ylaminoJ phenti,!}-cis-2,6-dimethy! piperazine-l-carboxylic acid tert-bcityl ester Bv substituting 4-[4-(7-amino-pyrido[2,3-d]pyrimidin-2-ylamino)-phenyl]-cis-2.6-dimethyl-piperazine-1-carboxylic acid tert-butyl ester (Example 27) for N2-phenyl-pyrido[2.3-d]pvrimidine-2,7-diamine in Example 10, 0.1828 g (74.9%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 549.3: Found 549.4.

1-tert-Bufil-3-{2-[4-(cis-3,5-dimetht,! piperazin-1 y1) phenylaminoJ-pyrido[2,3-d1pyrimidin-7yl}-urea Bv substituting 4-{4-[7-(3-tert-butyl-ureido)-pyrido[2.3-d]pyrimidin-2-ylamino]-phenvl}-cis-2.6-dimethyl-piperazine-l-carboxylic acid tert-butvl ester (Example 28) for 4-{4-[7-(3-tert-butvl-ureido)-pvrido[2.3-djpvrimidin-2-vlamino]-phenvl}-piperazine-l-carboxvlic acid tert-butyl ester in Example 15 is obtained 0.0910 g(92.9 io) of the product (compound 49). mp 245 C (dec).
MS (APCI) M+1: Calcd 449.3; Found 449.2.

4-{4-[7-(3-Cyclohe.xf,l-ureido) pyrido[2,3-d]pyrimidin-2 -ylan:inoJ-phenI'l}-cis-2,6-dimethvl piperazine-l-carboxvlic acid tert-butt,l ester Bv substitutin2 cvclohexvl isocyanate for tert-butyl isocvanate in Example 28. 0.1156 g (60.8%) of the product is obtained as a solid.
MS (APCI) M+l: Calcd 575.3; Found 575.3.

1-Ct'clohe_ry1-3-[2-[4-(cis-3,5-dimethyl piperazin-l.t'1) pheirrla-nino]-phrido[2,3-dJpyrinnidin- 7-yl}-urea By substituting 4-{4-[7-(3-cvclohexvl-ureido)-pyrido[2.3-d]pvrimidin-2-vlamino]-phenyl }-cis-2.6-dimethyl-piperazine-l-carboxvlic acid tert-butvl ester (Example 30) for 4-{4-[7-(3-tert-butyl-ureido)-pyrido[2,3-d]pvrimidin-2-vlamino]-phenyl}-piperazine-l-carboxylic acid tert-butyl ester in Example 15, 0.1022 g of the product is obtained (compound 50), mp 228 C (dec).
MS (APCI) M+1: Calcd 475.2; Found 475.2.

4-{4-[7-(3-Cyclopentyl-ureido) pvrido[2,3-dJpyrimidin-2 ylaminoJ-phenl~lJ-piperazine-1-carboxylic acid tert-butyl ester To a solution of 0.150 g(0.'l 6 mmol) of 4-[4-(7-amino-pyrido[2.3-d]pvrimidin-2-vlamino)-phenvl]-piperazine-l-carboxvlic acid tert-butvl ester (Example 13) in 2 mL of dimethvlformamide, cooled in an ice bath, is added 0.022 g (0.54 mmol) of 60% sodium hydride. The cooled solution is stirred for 15 minutes, then treated with 0.088 g (0.54 mmol) of carbonvldiimidazole. The cooled solution is stirred for another 30 minutes. then treated with 0.071 mL
(0.72 mmol) of cvclopentvlamine. The resulting solution is stirred at room temperature for 1 hour. then added to cold water. The solid is collected by filtration to give a first crop of material. The aqueous filtrate is then extracted with dichloromethane. and the extracts are dried (magnesium sulfate) and concentrated to give a second crop of material. The 2 crops are combined and purified by flash chromatography. eluting with a gradient of 0% to 5% methanol/dichloromethane durinu 30 minutes to give 0.1159 g(60.4%) of the product as a solid.

MS (APCI) M+1: Calcd 533.3: Found 533.4.

I-Cclopentvl-3-[2-(4 piperazin-1 yl phenvlamino)p'rido[2,3-dlpti,rimidin-7 y1J-urea By substitutinp- 4-{4-[7-(3-cyclopentvl-ureido)-pyrido[2.3-d]p,,rimidin-2-vlamino]-phenyl}-piperazine-l-carboxylic acid tert-butyl ester (Example 32) for 4- { 4-[7-(3-tert-butvl-ureido )-pvrido [2,3 -d]pyrimidin-2-ylamino]-phenyl } -piperazine-1-carboxylic acid tert-butyl ester in Example 15, 0.0937 g (80.8%) of the product (compound 5 1) is obtained, mp 210-213 C (dec).

MS (APCI) M+1: Calcd 433.2; Found 433.2.

Anal. Calc for C23H-?8Ng01-2.49 HCl=1.65 H2O=0.1 dioxane:
C, 50.02: H. 6.21: N. 19.94: Cl (total), 15.71.
Found: C, 49.89; H. 5.81: N. 19.74; Cl (total). 14.74.

1-(4 Amino-2-methylsulfanti,l pvrimidin-5 y1)-ethanol To a suspension of 5.0 R(29 mmol) 4-amino-2-methylsulfanvl-pvrimidine-5-carboxaldehvde (Example 3) in 150 mL of tetrahvdrofuran, cooled by an ice bath. is added during 20 minutes. 23.2 mL of a 3.0 M methvlmaQnesium bromide solution in diethvl ether (69.4 mmol). After 1 hour at 0 C, another 23.2 mL of the 3.0 M methvlmaLynesium bromide solution is added. and the suspension is allowed to come to room temperature and stirred overniaht. The reaction is quenched with 100 mL of saturated aqueous ammonium chloride. and partitioned between water and ethvl acetate. The organic laver is dried (mainesium sulfate) and concentrated to give 5.24 g(96%) of the product, mp 140-142 C.
MS (APCI) M+1: Calcd 186.1: Found 185.9.

1-(4-Amino-2-medtvlsulfanvl pyrintidin-S yl)-ethanone By substitutini! 1-(4-amino-2-methvlsulfanvl-pvrimidin-5-till)-ethanol (Example 34) for (4-amino-2-meth~,lsulfanvl-pyrimidin-5-vl )-methanol in WO 01/55147 PCT/IBOl/00069 Example 3 and conducting the reaction at 80 C in toluene. 3.74 g(72%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 184.0; Found 183.9.

1-(4 Amino-2-methanesulfinylprimidin-5 }~l)-ethanone Bv substituting 1-(4-amino-2-methvlsulfanyl-p~,rimidin-5-vl)-ethanone (Example 35) for 2-methylsulfanyl-pyrido[2.3-d]pyrimidin-7-vlamine in Example 8, 9.57 c, (88%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 200: Found 200.

4-[4-(5 Acetyl-4-aminoprimidin-2 ylamino) pheyryl]piperazine-l-carboxylic acid tert-butyl ester Bv substituting 1-(4-amino-2-methanesulfinyl-pyrimidin-5-N,1)-ethanone (Example 36) for 2-methanesulfinyl-p~-rido[2.3-d]pyrimidin-7-~,lamine in Example 13, 4.04 g(65 /o) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 413; Found 413.

4-[4-(7-Amino-5-methyl pt'rido[2,3-dJpvrimidin-2-1,lami-to) phenti=lJ-piperazine-1-carboxi.,lic acid tert-butvl ester To a suspension of 0.58 g (14.6 mmol) of 60% sodium hydride in 10 mL of tetrahydrofuran. at 0 C. is added dropxvise 2.58 g (14.56 mmol) of diethyl (cyanomethyl) phosphonate. The reaction mixture is stirred at 0 C for 5 minutes, then at room temperature for 20 minutes. The mixture is then cooled to 0 C and treated with 2 a(4.85 mmol) of 4-[4-(5-acetvl-4-amino-p~'rimidin-2-ylamino)-phen},l]-piperazine-l-carboxN,lic acid tert-butvl ester (Example 37). The mixture is stirred at room temperature overnight, and then treated with water and saturated aqueous ammonium chloride. The resulting solid is collected by filtration and washed ,vith ether to give 1.069 p- (80%) of the product.
MS (APCI) M+l: Calcd 436: Found 436.

WO 01/55147 PCT/IBOl/00069 4-{4-[7-(3-Cvclohexyl-ureido)-5-meNr_yl pyrido[2,3-dJpt,rin:idirr-2-t,latrrinoJ-phenyl} piperazine-l-carboxvlic acid tert-butvl ester Bv substituting 4-[4-(7-amino-5-methyl-p_yri do [2.3-d]pvrimidin-2-ylamino)-phenyl]-piperazine-l-carboxvlic acid tert-butyl ester (Example 38) for 4-[4-(7-amino-pvrido[2,3-d]pvrimidin-2-vlamino)-phenyl]-piperazine-l-carboxylic acid tert-butl ester in Example 16. 0.199 2 (42%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 561; Found 561.

1-Cclohek-vl-3-[5-methyl-2-(4 piperazirt-1 yl phenvlamino)-pyrido[2,3-dJpyrimidin-7 y1J-urea By substituting 4-{4-[7-(3-cyclohexyl-ureido)-5-methyl-pyrido[2.3-d]pyrimidine-2-vlamino]-phenyl; piperazine-l-carboxylic acid tert-butvl ester (Example 39) for 4-{4-[7-()-tert-butyl-ureido)-pyrido[2,3-d]pyrimidin-2-vlamino]-phenyl}-piperazine-l-carboxylic acid tert-butyl ester in Example 15, the product (compound 12) as a solid is obtained. mp 238 C (dec).

MS (APCI) M+1: Calcd 461: Found 461.

5-Met/r_yl-2-met/tylsulfant'1 pt,rido[2,3-dJpvrimidin-7-ylamine Bv substituting 1-(4-amino-2-methylsulfanvl-pyrimidin-5-vl)-ethanone (Example 35) for 4-[4-(5-acetvl-4-amino-pyrimidin-2-vlamino)-phenyl]-piperazine-l-carboxylic acid tert-butyl ester in Example 38, 0.97 g (85%) of the product as a solid is obtained.
MS (APCI) M+l: Calcd 207: Found 207.

2-Methanesuljn1-l-5-methyl pi,rido[2,3-dJpl,rimidin-7-vlanrine By substituting 5-meth\-l-2-methylsulfanyl-pvrido[2.3-d]pvrimidin-7-vlamine (Exaniple 41) for 2-meth~'lsulfanyl-pyrido[2.3-d]pyrimidin-7-ylamine in Example S. 0.85 -, (83%) of the product as a solid is obtained.

MS (APCI) M+1: Calcd 223; Found 223.

4-[4-(7-Amino-5-meth yl-p yrido[2, 3-dJpyrimidin-2-ylamino)-ph eir ylJ-piperazin e-1-carboxvlic acid tert-buh~l ester By substituting 2-methanesulfinvl-5-methyl-pvrido[2.3-d]pvrimidin-7-vlamine (Example 42) for 2-methanesulfinyl-pyrido[2.3-d]pyrimidin-7-ylamine in Example 13, 0.33 g (20%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 436: Found 436.

4-[4-[7-(3-tert-Butyl-ureido)-5-met/ryl pyrido[2,3-dJpyrimidiii-2-ylamino]-phenyl} piperazine-l-carbox},lic acid tert-butyl ester By substituting 4-[4-(7-amino-5-methyl-pvrido[2,3-d]pvrimidin-2-ylamino)-phenyl]-piperazine-l-carboxylic acid tert-butyl ester (Example 43) for N2-phenyl-pyrido[2.3-d]pyrimidine-2,7-diamine in Example 10. 0.17 g (45%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 535; Found 535.

1-tert-Butvl-3-[5-methyl-2-(4 piperazin-1 },! phenylamino)-pyrido[2,3-dJpyrimidin- 7 .ylJ-urea By substituting 4-{4-[7-(3-tert-butyl-ureido)-5-methyl-pyrido[2,3-d]pyrimidin-2-vlamino]-phenyl}-piperazine-l-carboxylic acid tert-butyl ester (Example 44) for 4-{4-[7-(3-tert-but-,,l-ureido)-pvrido[2,3-d]pyrimidin-2-ylamino]-phenyl}-piperazine-1-carboxvlic acid tert-butyl ester in Example 15, 0.070 g (72%) of the product (compound 4) as a solid is obtained. mp 230-232 C
(dec).
MS (APCI) M+l: Calcd 435: Found 435.

6-FI uoro-2-meth_ylsulfanyl-8H-pvrido[2,3-d]pyrimidin-7-one A solution of 1.74 g (10.33 mmol) of (diethoxv-phosphoryl)-fluoro-acetic acid ethvl ester in 20 mL of tetrahydrofuran is cooled to -78 C and treated dropwise with 12.9 mL (20.65 mmol) of a 1.6 M solution of n-butvl lithium in hexanes. After stirring for 30 minutes at -78 C, the solution is treated with 1.74 g (10.33 mmol) of 4-amino-2-methylsulfanyl-pyrimidine-5-carboxaldehyde (Example 3). allowed to warm to room temperature. and stirred overnight. The reaction is treated with saturated aqueous ammonium chloride, then water. The solid is collected by filtration and washed with diethyl ether to give 2.01 g(92%) of the product.
MS (APCI) M+1: Calcd 212: Found 212.

7-Chloro-6-[luoro-2-methtylsulfanyl pyrido[2,3-dJpyrimidine By substituting 6-fluoro-2-methylsulfanyl-8H-pyrido[2,3-d]pyrimidin-7-one (Example 46) for 2-methylsulfanyl-8H-pyrido[2,3-d]pyrimidin-7-one in Example 6 is obtained 1.86 g(85%) the product as a solid.
MS (APCI) M-'-1: Calcd 230. 232; Found 230. 2.3 )2.

6-Fluoro-2-metlrvlsulfanti,l pti,rido[2,3-dJpyrintidine-7-vlanune By substituting 7-chloro-6-fluoro-2-methylsulfanyl-pyrido[2,3-d]pyrimidine (Example 47) for 7-chloro-2-methvlsulfanyl-pyrido[2.3-d]pyrimidine in Example 7 is obtained 0.29 g (90%) of the product as a solid.
MS (APCI) M+1: Calcd 211: Found 211.

6-Fluoro-2-methanesulfin1!l pvrido[2,3-dJpy,rimidin-7 ylarnine By substituting 6-fluoro-2-methvlsulfanyl-pyrido[2.3-d]pyrimidin-7-ylamine (Example 48) for 2-methylsulfanyl-pyrido[2,3-d]pyrimidin-7-ylamine in Example 8. 0.26 g (95%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 227: Found 227.

4-[4-(7-Amino-6 fluoroprido[2,3-dJpvrintidin-2-l'lamino) phen1,1J-cis-2,6-dimethy!-piperazine-l-carboxvlic acid tert-butvl ester BN, substitutinE 6-fluoro-2-methanesulfinvl-pvrido[2.3-d]pvrimidin-7-ylamine (Example 49) for 2-methanesulfinyl-pyrido[2. 3 -d]pvrimidin-7-vlamine in Example 27. 0.040 g (63%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 468; Found 468.

4-{4-[7-(3-Ct,clohex},1-ureido)-6 fTuoro pl,rido[2,3-dJpi,ritnidin-2 _ti,laminoJ-phenti,lJ-cis-2,6-dimeth1,1piperaziire-l-carbox-i=lic acid tert-buh'l ester By substituting 4-[4-(7-amino-6-fluoro-pvrido[2,3-d]pvrimidin-2-vlamino)-phenvl]-cis-2.6-dimethyl-piperazine-l-carboxvlic acid tert-butyl ester (Example 50) for 4-[4-(7-amino-pyrido[2.3-d]pvrimidin-2-vlamino)-phenyl]-piperazine-l-carboxylic acid tert-butyl ester in Example 16. 0.10 g (74%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 593: Found 593.

1-Cyclohexvl-3-{2-[4-(cis-3,5-dimetht,l piperaziir-1-1,1) pheirt'laminoJ-6-Jluoro-pyrido[2,3-dJpl!rimidin-7-ylJ-urea Bv substituting 4-}4-[7-(3-cyclohex~,l-ureido)-6-fluoro-pyrido[2.3-d]pvrimidin-2-vlamino]-phenvl}-cis-2.6-dimethvl-piperazine-l-carboxylic acid tert-butvl ester (Example 51) for 4-}4-[7-(3-tert-butvl-ureido)-pvrido[2.3-d]pyrimidin-2-vlamino]-phenyl }-piperazine- l -carboxylic acid tert-butyl ester in Example 15, 0.060 g(75%) of the product (compound 52) as a solid is obtained, mp 227-229 C.
MS (APCI) M+l : Calcd 493: Found 493.

4-{4-[7-(3-Cyclopenh,l-ureido)-S-methylpyrido[2,3-dJpyrimidin-2 ylaminoJ-phenyl} piperazine-l-carboxylic acid tert-butyl ester Bv substituting 4-[4-(7-amino-5-methyl-pvrido[2.3-d]pvrimidin-2-vlamino)-phenvl]-piperazine- l -carboxylic acid tert-butvl ester (Example 43 ) for 4-[4-(7-amino-pvrido[2.3-d]pvrimidin-2-vlamino)-phenvl]-piperazine-l-carboxvlic acid tert-butvl ester in Example 32. 0.18 g (55%) of the product as a solid is obtained.
N1S (APCI) M+l : Calcd 547; Found 547.

1-Ct'clopenh~l-3-[5-ntethyl-2-(4 piperazin-1 yl phenvlantino)-pyrido[2,3-dJpyrimidin-7 y!J-urea Bv substituting 4-{4-[7-(3-cyclopentvl-ureido)-5-methyl-pvrido[2,3-d]pvrimidin-2-vlamino]-phenyl}-piperazine-l-carboxylic acid tert-butyl ester (Example 53) for 4-{4-[7-()-tert-butyl-ureido)-pvrido[2.3-d]pvrimidin-2-vlamino]-phenvl}-piperazine-l-carboxvlic acid tert-butvl ester in Example 15, 0.08 g(70%) of the product (compound 53) is obtained. mp 234 C (dec).

MS (APCI) M+1: Calcd 447: Found 447.

4-(4-{7-[3-(3-Hydrozy-propy!)-ureidoJ-pyrido[2,3-dJpyrimidin-2-t'lantino}-pheny!) piperazine-l-carboxt,lic acid tert-bufil ester Bv substituting 3-amino-l-propanol for cvclopentvlamine. and sodium tertiarv butoxide for sodium h%,dride in Example 32. 0.1295 g (52.2%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 523.3: Found 523.2.

1-(3-Hydro_rti propt,l)-3-[2-(4 piperazin-1-ylphen_ylantino) pyrido [2,3-d1pyrintidin- 7-y!/-urea B%, substituting the product of Example 55 in Example 15. 0.1077 g of the product (compound 81) as a solid is obtained. mp 183 C (dec).

MS (APCI) M+1: Calcd 423.2; Found 423. l.

4-{4-[7-(3-Cclohexy1-3-n:ethyl-ureido) pvrido[2,3-dJpyrifnidin-2-vlaminoJ-phenyl]piperazine-l-carbo.xylic acid tert-buhl ester B}, substitutina N-methylc'Iclohexylamine for 3-amino-l-propanol in Example 55. 0.1932 g(72.7%) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 561.3; Found 561.2.

1-Cvclohexvl-l-metht,l-3-[2-(4 piperazin-1-v1 phenylamino) pt=rido [2,3-dJpyrintidin-7-YI]-urea By substituting the product of Example 57 in Example 15. 0.1645 g of the product (compound 65) as a solid is obtained, mp 177 C (dec).
MS (APCI) M+l : Calcd 461.3: Found 461.2.

4-(4-{7-[3-((S)-1-Hvdrotvmetlrl,1-3-n:ethvl-buryl)-ureidoJ pvrido [2,3-d]pvrimidin-2-vlamino} phen_vl) piperazine-l-carbo.x-i~lic acid tert-buh'l ester Bv substituting (S)-(+)-leucinol for 3-amino-l-propanol in Example 55, 0.1048 g(39.1 ro) of the product as a solid is obtained.
MS (APCI) M+1: Calcd 565.3: Found 565.3.

1-((S)-1-Hvdroxymet/zyl-3-meNtvl-butyl)-3-[2-(4 piperazin-1-v1 phenvlamino)-pvrido[2,3-dJpvrimidin-7-vlJ-urea By substituting the product of Example 59 in Example 15. 0.0802 g of the product (compound 83) as a solid is obtained, mp 185 C (dec).

MS (APCI) M+1: Calcd 465.3; Found 465.2.

4-[4-(7-{[]-(4-Mediyl piperazin-1 yl)-methanoilIJ-amino} pvrido[2,3-dJpyrimidin-2-vlamino) phenylJ-piperazine-l-carboxylic acid tert-buttI ester Bv substitutinQ N-methylpiperazine for 3-amino-l-propanol in Example 55. the product as a solid is obtained.
MS (APCI) M+l: Calcd 548.3; Found 548.3.

4-Methyl piperazine-l-carboxvlic acid [2-(4 piperazin-1 yl phenvlamino)-pj,rido[2,3-dJpvrimidin-7-ylJ-arnide By substituting the product of Example 61 in Example 15, 0.1194 g of the product (compound 84) as a solid is obtained, mp 200 C (dec).

MS (APCI) M+l,: Calcd 448.3; Found 448.2.

4-(4-{7-[(1-Morpl:olin-4 .ti!l-nrethanoyl)-an:inoJ-pyrido[2,3-dJpyrintidin-2-ylamino} phenyl) piperazine-l-carboxvlic acid tert-butyl ester By substituting morpholine for 3-amino-l-propanol in Example 55. the product as a solid is obtained.
MS (APCI) M+1: Calcd 535.3: Found 535.2.

Morpholine-4-carboxylic acid [2-(4 piperazin-1 .vl p/ten_vlantino) pvridu[2,3-dJpvrinzidin-7 y1J-amide Bv substituting the product of Example 63 in Example 15, 0.1132 g of the product (compound 85) as a solid is obtained. mp 190 C (dec).

MS (APCI) M+1: Calcd 435.2; Found 435.2.

4-{4-[7-(3,3-Dipropvl-ureido)-pvrido[2,3-dJpvrimidin-2 yla-ninoJ-phenvl}-piperazine-1-carbo.zylic acid tert-butyl ester B}, substituting dipropylamine for 3-amino-l-propanol in Example 55, the product as a solid is obtained.

MS (APCI) M+1: Calcd 549.3: Found 549.3.

3-[2-(4-Piperazin-1-ti,1 phenvlamino) pvrido[2,3-dJpti,rimidin-7-y1]-1,1-dipropyl urea By substitutina the product of Example 65 in Example 15, 0.1278 g of the product (compound 86) as a solid is obtained, mp 190 C (dec).
MS (APCI) M+1: Calcd 449.3; Found 4492 .

4-[4-(7-{[]-(4-Boc piperazin-1-i,1)-nzetltanoti,lJ-amino} pyrido[2,3-d]pti,rimidin-2-Vlamino) phenvlJ piperazine-l-carboxylic acid tert-bufil ester Bv substituting Boc-piperazine for 3-amino-l-propanol in Example 55. the product as a solid is obtained.
MS (APCI) M+1: Calcd 634.3; Found 634.3.

Piperazine-1-carboxy,lic acid [2-(4 piperazirn-1 yl pl:enti,lanrino)p'rido[2,3-dJpyrimidin-7 yl]-anzide Bv substituting the product of Example 67 in Example 15. 0.0342 g of the product (compound 87) as a solid is obtained. mp 220 C (dec).

MS (APCI) M+1: Calcd 434.2: Found 434.2.

4-(4-{7-[3-((R)-1-Hhdroxvmethy,l-2-met/rv! propyl)-ureidoJ-pyrido[2,3-dJpyrimidin-2-ylamino} phenyl) piperazine-l-carbatl,lic acid tert-butyl ester By substituting (R)-valinol for 3-amino-l-propanol in Example 55, the product as a solid is obtained.
MS (APCI) M+l: Calcd 551.3: Found 551.3.

1-((R)-1-Hydroxvmethyl-2-methyl propyl)-3-[2-(4 piperazin-1 yl phenvlamino)-pvrido[2,3-dlpyrimidin- 7-y1]-urea Bv substituting the product of Example 69 in Example 15. 0.0639 g of the product (compound 88) as a solid is obtained. mp 200 C (dec).
MS (APCI) M+1: Calcd 451.3; Found 451.2.

4-(4-{7-[3,3-Bis-(2-hydro.x-t,-ethyl)-ureido]-pyrido[2,3-dJpyrinridin-2-ylamin o}-pheiTt,1) piperazine-l-carboxylic acid tert-butyl ester Bv substituting diethanolamine for 3-amino-1-propanol in Example 55, the product as a solid is obtained.
MS (APCI) M+1: Calcd 553.3: Found 553.2.

1,1-Bis-(2-lrydroxy-eNryl)-3-[2-(4 piperazin-1 yl phenylantino) pyrido[2,3-dJpyriniidin-7 y1J-urea By substituting the product of Example 71 in Example 15. 0.0916 g of the product (compound 89) as a solid is obtained. mp 185 C (dec).
MS (APCI) M+1: Calcd 453.2: Found 453?.

6-Bromo-2-n:ethylsulfan1,1-8H-pt=rido[2,3-dJpvrimidin-7-one To 5.00 g (25.9 mmol) of 2-methanesulfanyl-BH-pyrido[2.3-d]pyrimidin-7-one (Example 5) in 130 mL of DMF is added 5.00 g (28.1 mmol) of N-bromosuccinimide. The resulting suspension is stirred at room temperature overniaht and concentrated. The solid is triturated with hot water. then washed with isopropanol to give 5.59 ~(79.4 0) of the product as a solid. mp 266-270 C.

6-Bromo-7-chloro-2-methylsulfanyl pyrido[2,3-dJpvrimidine By substituting the product of Example 73 in Example 6. 2.73 g (97.2%) of the product is obtained as a solid.

MS (APCI) M+1: Calcd 289.9: Found 289.8.

6-Bronto-2-meth yls ulfan yl p'rid o[2, 3-dJprintid in- 7-,yl amin e By substituting the product of Example 74 in Example 7. 2.09 ~(82.9%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 271.0: Found 270.8.

6-Bronto-2-ntethanesulfinyl-pti,rido[2,3-dJpyrintidin- 7-14amine By substituting the product of Example 75 in Example S. 1.81 g (81.9%) of the product is obtained as a solid, mp 245 C (dec).

MS (APCI) M+1: Calcd 287.0; Found 286.8.

4-[4-7-Antino-6-bromo pvrido[2,3-dJpyrimidin-2 ylantino) phenylJ-piperazine-I-carboxylic acid tert-butyl ester By substituting the product of Example 76 in Example 13, 1.40 g (44.4%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 500.1; Found 500Ø

4-{4-[6-Bromo-7-(3-cyclohe.zyl-ureido) pt,rido[2,3-dJpt'rimidin-2 ylaminoJ-phenyl} piperazine-l-carboxylic acid tert-butti=l ester By substituting the product of Example 77 in Example 16, 0.1160 g (46.4%) of the product is obtained as a solid.
MS (APCI) M+l: Calcd 625.2: Found 625.1.

1-[6-Bronto-2-(4 piperazin-1-y1 pltenylantino)prido[2,3-dJpllrintidin-7-ylJ-3-cyclolte.rhl-ttrea Bv substituting the product of Example 78 in Example 15. 0.0886 g (77.0%) of the product (compound 55) is obtained as a solid. mp 195 C (dec).

MS (APCI) M+l: Calcd 525.2: Found 525.1.

Anal. Calcd for C24H29BrINgO1-1.64 H20-1.83 HCI:
C. 46.37: H. 5.53: N, 18.02; Cl. 10.44.
Found: C. 46.53: H. 5.34: N. 17.73: Cl. 10.15.

4-{4-[6-Bromo-7-(3-tert-butvl-ureido) pyrido[2,3-dJpyrimidin-2ylamino]-phenvl} piperazine-l-carbo.xylic acid tert-butvl ester BN, substituting the product of Example 77 in Example 10, 0.2571 g (42.9 ro) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 599.2; Found 599.2.

1-[6-Bromo-2-(4 piperazin-1 yl phenylamino) pvrido[2,3-d]pyrintidin-7 y1J-3-tert-bu4,l-urea BN, substituting the product of Example 80 in Example 15, 0.0481 g of the product (compound 91) is obtained as a solid.
MS (APCI) M+1: Calcd 499.2: Found 499Ø

4-{4-[6-Bromo-7-(3-methyl-ureido) pvrido[2,3-dJpvrin:idin-2 ylaminoJ-phenyl}-piperazine-1-carboaylic acid tert-butyl ester BN, substituting the product of Example 77 and methylamine in Example 32, 0.170 g(29.9 ro) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 557.2: Found 557.1.

1-[6-Bromo-2-(4 piperaznl-I-v1 phenvlamino) pvrido[2,3-dJpy,rimiditr-7 y1J-3-inethyl-urea BN, substitutina the product of Example 82 in Example 15, 0.0963 g (69%) of the product (compound 93) is obtained as a solid.
MS (APCI) M+1: Calcd 457.1: Found 457.1.

Anal. Calcd for C 19H~ I BrI N8O 1=3 HC1=3 H2O:

C. 36.76: H. 4.87; N. 18.05; Cl. 17.13; H20. 8.71.
Found: C, 36.49: H. 4.35; N. 17.52; Cl. 15.79: H-)O, 8.12.

4-[4-(7 Antino-6-brofno pvrido[2,3-dJpvrin:idin-2-vlamino) phen}'lJ-cis-2,6-dimet/ryl piperazine-l-carbo.aylic acid tert-butt,l ester Bv substituting the product of Example 76 in Example 27. 2.10 g(63.1 %) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 528.2; Found 528.2.

4-{4-[6-Bromo-7-(3-tert-butyl-ureido) pvrido[2,3-dJpvrimidin-2 ylaminoJ-pheiryl}-cis-2,6-dimethvl piperazlne-l-carboxvlic acid tert-butvl ester By substituting the product of Example 84 in Example 10. 0.1725 g (72.6%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 627.2: Found 627?.

1-{6-Bronro-2-[4-(cis-3,5-dimethvl pipera<,in-1-v1) phe-rvlanrinoJ-pvrido[2,3-dJpvrimidin-7-y1}-3-tert-butvl-urea By substituting the product of Example 85 in Example 15. 0.1593 g (96.0%) of the product (compound 94) is obtained as a solid. mp 202 C (dec).
MS (APCI) M+1: Calcd 527.2; Found 527.2.

Anal. Calcd for C-24H~ I BrIN8O1 -2.55 HC1= 1.70 H-) O:
C. 44.28: H. 5.71 N. 17.21: Cl. 13.89.
Found: C. 44.28; H. 5.72: N. 17.09: Cl. 12.49.

4-{4-[6-Bronto-7-(3-cvc/ohexyl-ureido) pvrido[2,3-dJpvrintidin-2ylantinoJ-phenvl}-cis-2,6-dimeth_vl-piperazine-l-carboxvlic acid tert-bufil ester Bv substituting the product of Example 84 in Example 16. 0.1750 c, (70.7%) of the product is obtained as a solid.
MS (APCI) M+l: Calcd 653.3; Found 653.3.

1-[6-Bronto-2-[4-(cis-3,5-dimetht'! piperazin-1-v1) phenvlaminoJ-pvrido[2,3-d]pvrintidin-7 y!}-3-cl!clohexti,!-urea By substituting the product of Example 87 in Example 15. 0.1614 g (95.4%) of the product (compound 95) is obtained as a solid. mp 198 C (dec).
MS (APCI) M+1: Calcd 553.2: Found 553?.

Anal. Calcd for C26H33N8O1Brl =2.76 HCl=2.02 H2O:
C. 45.22: H. 5.81: N. 16.23: Cl. 14.17.
Found: C, 45.23: H. 5.82; N. 16.08: Cl, 13.53.

N2-(4-Fluoro phenyl) pvrido[2,3-dJpvrintidine-2,7-diantine Bv substitutinQ 4-fluoroaniline in Example 9. 1.1529 Q (45?%) of the product is obtained as a solid. mp 245-248 C.
MS (APCI) M+1: Calcd 256.1; Found 255.9.

1-[2-(4-Flttoro pltenvlantino) phrido[2,3-dJpvrimidut-7-I,1/-3-(3-ntorpholin-4 y!-propv!)-urea Bv substitutinQ the product of Example 89 and 3-morpholin-4-vl-propvlamine in Example 32. 0.1465 R(58.6 ro) of the product (compound 96) is obtained as a solid. mp 253-256 C.

MS (APCI) M+l: Calcd 426.2: Found 426.1.

Anal. Calcd for C-) 1 H24F I N702:

C. 59.2 S. H. 5.69; N. 23.04.
Found: C. 59.18: H. 5.66: N. 23.04.

1-[2-(4-Fluoro phenylantino) pyrido[2,3-dJpyrintidin-7-y1J-3-(2-ltydroiy-ethyl)-urea Bv substituting the product of Example 89 and 2-hydroxy-ethylamine in Example 32. 0.0811 a(40.3 ro) of the product (compound 97) is obtained as a solid, mp 238-240 C.
MS (APCI) M+1: Calcd 343.1: Found 343.1.
Anal. Calcd for CI6H15F1N602:

C. 56.14; H. 4.42; N. 24.55.
Found: C. 55.82: H. 4.52: N. 24.15.

1-(2 Antino-ethyl)-3-[2-(4 Jluoro phenylantino) pyrido[2,3-dJpyrintidin-7 y!J-urea By substituting the product of Example 89 and ethylenediamine in Example 32. 0.1000 g(49.3 io) of the product (compound 98) is obtained as a solid, mp 217-220 C.
MS (APCI) M+1: Calcd 342.1; Found 342Ø
Anal. Calcd for C16H16FIN7O1=0.2 H-)O:
C, 55.71; H. 4.79; N. 28.42.
Found: C. 55.72: H. 4.57: N. 28.07.

1-(2-Dimethylantino-eNtt'I)-3-[2-(4 fluoro-phenylafnino) pyrido[2,3-dlpyrintidin-7-_y1J-urea By substituting the product of Example 89 and 2-dimethylamino-ethvlamine in Example 32. 0.0778 ~(35.8 o) of the product (compound 99) is obtained as a solid. mp 251-255 C.

MS (APCI) M+1: Calcd 370.2; Found 370Ø

Anal. Calcd for C I 8H20F I N701:
C, 58.53; H, 5.46; N, 26.54.
Found: C. 58.39: H. 5.51; N. 26.26.

3,3-Dintethyl-l-(4-nitro pheny!) piperazine B~, substituting 2,2-dimethyl-piperazine in Example 24, 29.43 g(88.4 /0) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 236; Found 236.

2-2-Dintethyl-4-(4-nitro phenyl) piperazine-l-carboxylic acid tert-butvl ester By substituting the product of Example 94 in Example 11, 38 g (93%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 336: Found 336.

4-(4 Amino phe-{ti,!)-2,2-dimethy! piperazine-1-carboxvlic acid tert-butvl ester By substituting the product of Example 95 in Example 12. 27 g (78%) of the product is obtained as a solid.
MS (APCI) M+l: Calcd 306: Found 306.

4-[4-(7-A min o-6Jluoro pvrido[2,3-d]pvrintidin-2 ylamino) phenylJ-2,2-dimetlty!-piperazine-l-carboxvlic acid tert-butvl ester By substituting the product of Example 96 in Example 50, 0.4346 g (59.0%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 468.2: Found 468.3.

4-{4-[7-(3-Cyclohexyl-ureido)-6 fluoro pyrido[2,3-dJpyrimidin-2 ylanrinoJ-phenyl}-2,2-dimethyl piperazine-l-carbozylic acid tert-buh'l ester Bv substituting the product of Example 97 in Example 16, 0.170 g(31.2%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 593.2; Found 593.4.

1-Cyclohezyl-3-{2-[4-(3,3-dimethy! piperazin-1-y!) phenylaminoJ-6 Jluoro-pyrido[2,3-dJpyrimidin-7-yl]-urea Bv substituting the product of Example 98 in Example 15. 0.040 g of the product (compound 100) is obtained as a solid.
MS (APCI) M+1: Calcd 493.3; Found 493.2.

4-[4-(7 Amino-6-fluoro pyrido[2,3-dJpi,rimidin-2 ylamino) pheirylJ-piperazine-1-carboxt-'lic acid tert-butvl ester By substituting the product of Example 12 in Example 50. 0.2017 g (29.7%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 440.2; Found 440.2.

4-{4-[7-(3-Ct'clohexy!-ureido)-6 fluoro pyrido[2,3-dJpyrimidin-2 .ylaminoJ-p/:eny!} piperazine-l-carboxylic acid tert-butyl ester Bv substituting the product of Example 100 in Example 16. 0.2036 g (78.6%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 565.3: Found 565.3.

1-Cyclohexyl-3-[6 fluoro-2-(4 piperazin-1-y! phenylamirno) pyrido[2,3-dJpyrimidin-7-_ylJ-urea Bv substituting the product of Example 101 in Example 15. 0.1084 g (96.0 io) of the product (compound 11) is obtained as a solid.

MS (APCI) M+1: Calcd 465.2: Found 465.2.

Anal. Calcd for C24H29F I N8O 1=2.75 HC1=3.5 H2O:

C. 45.91; H. 5.10; N, 17.85; Cl. 15.53; H2O, 10.04.
Found: C. 46.20; H, 5.86: N, 17.45: Cl. 15.22: H-)O. 8.97.
~ EXAMPLE 103 4-{4-[7-(3-tert-Butvl-ureido)-6 fluoro pvrido[2,3-dJpvrin:idin-2-vlaaunoJ-phenvl}-cis-2,6-dimetlr-vl piperazine-l-carbo.zylic acid tert-but1I ester Bv substituting the product of Example 50 in Example 10. 0.070 g(17.9%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 567.3; Found 567.3.

1-tert-Butvl-3-{2-[4-(cis-3,5-dimetht,l piperazin-1 yl) phenvlaminoJ-6 JTuoro-pvrido[2,3-d]pi'rimidin-7-t'IJ-urea By substituting the product of Example 103 in Example 15. 0.0585 g of 1~ the product (compound 102) is obtained as a solid.
MS (APCI) M+1: Calcd 467.3: Found 467.3.

1-[4-(4-Nitro phenyl) piperazin},IJ-ethanone To a solution of 5.0 2 (24.1 mmol) of 1-(4-nitro-phenyl)-piperazine in 100 mL of dichloromethane ,vas added 5.04 mL (28.9 mmol) of diisopropyl-ethvlamine. The solution is cooled in an ice-bath. treated ,~vith 1.89 mL
(26.5 mmol) of acetyl chloride. and stirred at room temperature overnight. The reaction is -,vashed successivelv with water, 0.5 M HC1. saturated sodium hvdroaen carbonate. and brine, and dried over magnesium sulfate. and concentrated to give 5.91 2 (98.5%) of the product as a solid.
MS (APCI) M+1: Calcd 250.1: Found 250Ø

1-[4-(4 Amino phenvl) piperazin-1 y1J-ethanone By substituting the product of Example 105 in Example 12. 4.35 g (84.1%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 220.1; Found 220.1.

1-{4-[4-(7 Aminop,rido[2,3-dJpvrimidin-2 ylamino) phenv1J-piperazifi-1 yl}-etfhanone By substituting the product of Example 106 in Example 9, 0.1829 g (50.1 %) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 364.2; Found 364.2.
Anal. Calcd for C 19H2I N7O 1= 1.0 H20:

C, 59.46; H. 6.11; N. 25.55.
Found: C, 59.51; H. 6.03; N. 25.28.

1-{2-[4-(4 Acetv! piperazin-1 yl) phe-rvlaminoJ-pvrido[2,3-dJpvrin:idin-7-vl}-(3-morpholin-4 yl propvl)-urea By substituting the product of Example 107 and 3-morpholin-4-yl-propylamine in Example 32. 0.0338 g (22.6%) of the product (compound 103) is obtained as a solid, mp 222-225 C (dec).
MS (APCI) M+1: Calcd 534.3; Found 534.2.
Anal. Calcd for C27H35N9O3=0.5 H2O:

C. 59.76; H. 6.69: N. 23.25.
Found: C, 59.74; H. 6.53; N. 23.35.

6-Chloro-2-metlivlsulfanvl-8H-pvrido[2,3-dJpvrimidin-7-one By substituting N-chlorosuccinimide in Example 74, 0.3700 g(31.4%) of the product is obtained as a solid, mp 264-266 C (dec).
MS (APCI) M+1: Calcd 228.0: Found 227.9.

6, 7-Dichloro-2-methvlsulfanyl pyrido[2,3-d]pyrintidine By substituting the product of Example 109 in Example 6, 0.6534 g (86.5%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 246.0; Found 245.8.

6-Chloro-2-methvlsulfanyl pyrido[2,3-dJpyrimidin-7-ylantine BN, substituting the product of Example 110 in Example 7. 0.38 g (63%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 227.0: Found 226.9.

6-Chloro-2-methanesulfinyl pyrido[2,3-dJpyrintidin-7-ylantine By substitutina the product of Example 111 in Example 8, 0.2328 g (57.1%) of the product is obtained as a solid, mp 260-262 C.
MS (APCI) M+l : Calcd 243.0; Found 242.9.

4-[4-(7-Amino-6-chloro pyrido[2,3-dJpyrintidin-2-ylantino) phenylJ-cis-2,6-dinteNtyl piperazine-l-carboxylic acid tert-butyl ester By substitutin~ the product of Example 112 in Example 27, 0.22 g(49%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 484.2; Found 484.2.

4-[4-[7-(3-tert-Butyl-ureido)-6-chloro pyrido[2,3-dJpt'rimidin-2 ylaminoJ-phenyl}-cis-2,6-dintethyl piperazine-l-carboxti,lic acid tert-butyl ester By substituting the product of Example 113 in Example 10. 0.0995 g (39.2%) of the product is obtained as a solid.

1-tert-Butvl-3-{6-cltloro-2-[4-(cis-3,5-dimethvl piperazin-1-v1) phenvlaminoJ-pvrido[2,3-dJpvrimidin- 7-yl}-urea By substituting the product of Example 114 in Example 15. 0.0995 g of the product (compound 104) is obtained as a solid, mp 205 C (dec).

MS (APCI) M+1: Calcd 483.2: Found 483.2.

AIethyl-(2-methylsulfan1,1pvrido[2,3-dJpyrin:idin-7-yl)-an:ine By substituting methvlamine in Example 7. 1.46 g(30.0%) of the product is obtained as a solid.
MS (APCI) M+l: Calcd 207.1: Found 206.9.

(2-Methanesulfinyl p,rido[2,3-dJpvrimidin-7-y1)-methyl-amine By substituting the product of Example 116 in Example 8. 1.31 g(83.4%) of the product is obtained as a solid. mp 185 C.
MS (APCI) M+l : Calcd 223.1: Found 223Ø

4-[4-(7-Meth_ylamino pvrido[2,3-dJpvrinzidin-2 ylamino) phenv/J-piperazine-l-carboxvlic acid tert-buhl ester By substituting the product of Example 117 in Example 13. 0.4934 g (62.9%) of the product is obtained as a solid.
MS (APCI) M+1: Calcd 436.2: Found 436.2.

4-{4-[7-(3-Cvclohexvl-l-methi=l-ureido) pvrido[2,3-dJpyrimidin-2ylJ phenyl}-piperazine-1-carboxylic acid tert-butvl ester Bv substituting the product of Example 118 in Example 16. and using acetonitrile as solvent and no base. 0.8535 g (78.8%) of the product is obtained as a solid.
MS (APCI) M+l: Calcd 561.3: Found 561.3.

3-Cvclohexyl-l-methyl-l-[2-(4 piperazin-1 yl phenvlamino) pt,rido[2,3-dJpyrimidin-7-ylJ-urea Bv substituting the product of Example 119 in Example 15. 0.2548 ~
(36.0%) of the product (compound 70) is obtained as a solid. mp 169-175 C.
MS (APCI) M+1: Calcd 461.3; Found 461.2.

Anal. Calcd for C25H32N801-0.25 H2O:
C. 64.56: H, 7.04: N. 24.09.
Found: C. 64.57; H. 7.01: N. 23.98.

3-Cvclohexvl-l-{2-[4-(cis-3,5-dimethyl piperazin-1 yl) phent'laminoJ-pyrido[2,3-dJpyrimidin-7-yl]-1-nzethvl-urea Using the general procedure by which Example 120 is synthesized, 0.1366 g(95.6%) of the product (compound 106) is obtained as a solid, mp 170 C (dec).
MS (APCI) M+1: Calcd 489.3; Found 489.3.

Anal. Calcd for C27H36N8O1 =3.32 H-)0-2.69 HC1:
C. 50.16; H. 7.07; N. 17.33; Cl, 14.75.
Found: C. 50.36: H, 6.98: N. 16.97: Cl. 15.07.

3-Cvclohe_tvl-l-ethvl-l-[2-(4 piperazin-1 yl p/renvlamino) pvrido[2,3-dJ
pvrimidin-7 ylJ-urea Using the general procedure by which Example 120 is svnthesized, 0.118 g (94%) of the product (compound 107) is obtained as a solid.
MS (APCI) M+l : Calcd 475.3: Found 475.3.

Anal. Calcd for C26H;4?vgOl =3.0 HCl=0.3 diethylether:
C. 53.89: H. 6.65; N. 18.48.
Found: C. 53.75: H. 6.96: N. 18.57.

3-tert-Butvl-l-{2-[4-(cis-3,5-dimethvl piperazin-1 yl) phenvlan:inoJ-pl,rido[2,3-d]pyrimidin-7 yl}-1-ethvl-urea Using the general procedure by which Example 15 is synthesized, 0.022 g (56%) of the product (compound 108) is obtained as a solid.
MS (APCI) M+1: Calcd 477.3; Found 477.3.

1-Met/tl,l-3-[5-methv1-2-(4 piperazin-1-1,1 phen_vlantino)p,rido[2,3-dJpyrinridin-7ylJ-urea Using the general procedure by which Example 40 is synthesized, the product (compound 64) is obtained as a solid, mp 204-206 C (dec).

MS (APCI) M+1: Calcd 393; Found 393.

1-Et/tyl-3-[S-n:ethyl-2-(4 piperazin-I yl phenvlamino) pyrido[2,3-dJpvrimidin-7-ylj-urea Using the general procedure by which Example 40 is synthesized, the product (compound 28) is obtained as a solid. mp 220-222 C.

MS (APCI) M+1: Calcd 407: Found 407.

1-[S-Methyl-2-(4 piperazin-1 y! phenvlamino) pvrido[2,3-dJpvrimidin-7 y1J-3 propyl-urea Using the general procedure by which Example 40 is synthesized, the product (compound 111) is obtained as a solid, mp 223-225 C.

MS (APCI) M+1: Calcd 421: Found 421.

11;N-Dimethyl-N=[S-metltyl-2-[[4-(1 piperazinyl)phenylJ-ami oJ-pyrido[2,3-dJpyrimidin-7-_yl-sulfamide Using the general procedure by which Example 40 is svnthesized. but usina dimethyl sulfamyl chloride rather than cyclohexylisocvanate, the product (compound 71) is obtained as a solid. mp 228-230 C (dec).

MS (APCI) M+1: Calcd 443: Found 443.

7-Antino-2-ntethylsulfan_yl pyrido[2,3-dJpt'rintidine-6-carbo.x~,lic acid et/tyl ester To a solution of 4-amino-2-methanesulfanyl-pyrimidine-5-carboxaldehvde (Example 3) in 10 mL of tetrahydrofuran is added 0.126 mL (1.18 mmol) of ethyl cyanoacetate. The solution is cooled to -10 C, and treated with 2.36 mL

(2.36 mmol) of titanium tetrachloride. To the solution is slowly added 0.52 mL
(4.72 mmol) of N-methyl morpholine. The reaction is warmed to room temperature over 2 hours. and partitioned between ethvl acetate and saturated aqueous ammonium chloride. The organic laver is concentrated to give a solid, which is triturated with ether to give 0.30 g (96%) of the product as a solid.
MS (APCI) M+1: Calcd 265.1; Found 264.9.

7-Antitzo-2-chloro pyrido[2,3-dJpyrimidine-6-carbozylic acid ethyl ester To a suspension of the product of Example 128 in 50 mL of chloroform is slowly added sulfuryl chloride. followed by 2 drops of ethanol. The reaction is stirred at room temperature for 16 hours. poured into ether, and the solid collected to give 0.50 g (98%) of the product.
MS (APCI) M+1: Calcd 253.1: Found 253.1.

7-Antino-2-[4-(4-tert-butoxycarbonyl piperazin-1-y1) phenylantinoJ-pyrido[2,3-dJpt,rintidine-6-carboxylic acid etliyl ester A solution of the product of Example 12 and the product of Example 129 in dioxane is heated under reflux for 1.5 hours. The reaction is poured into hexane/ethyl acetate (1:1). and the solid is collected. Flash chromatography using dichloromethane as eluant gave 0.08 g (16%) of the product as a solid.
MS (APCI) M+1: Calcd 494.2; Found 494.1.

2-[4-(4-tert-Butoxtilcarbonyl piperazin-1 yl) phenl,lantinoJ-7-(3-tert-butl,l-ureido) pvridol2,3-dJpt,rintidine-6-carboxylic acid ethyl ester By substituting the product of Example 130 in Example 10. 0.05 g (48%) of the product as a solid is obtained.

7-(3-tert-Butvl-ureido)-2-(4 piperazin-1 yl phenylamino) pt'rido[2,3-dJpyrintidine-6-carboxvlic acid ethyl ester By substitutina the product of Example 131 in Example 15. 0.036 g of the product (compound 113) as a solid is obtained, mp >300 C.

]-[6-Fluoro-S-methyl-2-(4 piperazin-1-t'1 phen_ylantino) pt'rido(2,3-dJpj=rintidin-7-y1J-3-isopropvl-urea Using the general procedure bv which Example 52 is svnthesized, but using 1-(4-amino-2-methvlsulfan~,l-pyrimidin-5-vl)-ethanone (Example 35), 4-(4-amino-phenyl)-piperazine-l-carboxylic acid tert-butvl ester (Example 12). and isopropyl isocvanate as reagents. the product (compound 114) is obtained as a solid, mp 208 C (dec).
MS (APCI) M+1: Calcd 439.2: Found 439.3.

1-Cti,clohex_y1-3-{2-14-(3,3-dintethti=1 piperazin-1 yl) pheni'/aminoJ-pt,rido}2,3-dJpyrintidin-7-y1}-urea Using the general procedure by which Example 17 is svnthesized, but using 4-(4-amino-phenyl)-2.2-dimethyl-piperazine-l-carboxylic acid tert-butyl ester (Example 96). 0.95 g (100%) of the product (compound 115) is obtained as a solid.

MS (APCI) M+1: Calcd 475.6; Found 475.3.

Anal. Calcd for C26H34N8O1 =3 HC1-1 H-)O:

C. 51.96: H. 6.37; N. 18.64: Cl. 17.69: H,~O, 2.99.
Found: C. 52.00: H. 6.41: N. 18.53: Cl. 16.51: H-)O. 3.06.

6-Methyl-2-nret/t_ylsttlfanylprido[2,3-dJpyrimidin-7-ylamine To a suspension of 2.18 g (54 mmol) of 60% oil dispersed sodium hvdride in 300 mL of tetrahvdrofuran. cooled to 10 C, is added 10.2 ~(5 3.4 mmol) of (1-cvano-l-methvl-methvl)-phosphonic acid diethvl ester (Svnthesis. 1975:516).
To the cooled suspension is added 4.30 g(25.4 mmol) of 4-amino-2-methanesulfanyl-pvrimidine-5-carboxaldehvde (Example 3). and the reaction is stirred at room temperature for 22 hours. The resulting solution is concentrated and filtered to give a solid. which is washed ,vith tetrahvdrofuran. dissolved in 1N citric acid. and re-precipitated by adjusting the pH to 8 with 50% sodium hvdroxide. The solid is collected by filtration to give 1.1 g(21%) of the product, mp 268-270 C.
MS (APCI) M+1: Caled 207.3: Found 207Ø

1-Cy,clohexy1-3-{2-[4-(cis-3,5-dimeNry,l piperazin-1-y,l) phenti,laminoJ-6-met/ryl-pyrido[2,3-dJpyrimidin-7-171]-urea Using the general procedure by which Example 31 is synthesized, but usina the product of Example 135 as the starting material, 0.14 g(42 ro) of the product (compound 116) is obtained as a solid.
MS (APCI) M+1: Calcd 589.6: Found 589.3.

Anal. Calcd for C7H36N8O1=2.5 HC1.1.5 H-)O:

C. 53.80: H. 6.73: N. 18.01: Cl. 14.11: H-)O. 4.06.
Found: C. 53.44: H. 6.89: N. 18.46: Cl. 14.60; H-)O. 4.48.

1-tert-Butvl-3-{2 -14-(cis-3,5-dimethyl piperazin-1 yl) phenylaminoJ-6-ntethyl-pyrido[2,3-dJpyrimidin-7 yl}-urea Using the general procedure by which Example 29 is synthesized. but using the product of Example 135 as the starting material. 0.26 g (89%) of the product (compound 117) is obtained as a solid.
MS (APCI) M+1: Calcd 463.6; Found 463.3.
Anal. Calcd for C25H36N8O1 =2.4 HC1=1.75 H-)O:

C. 51.62; H. 6.91; N, 19.26; Cl. 14.63; H-)O. 5.42.
Found: C. 51.23; H. 6.55; N. 18.92; Cl, 14.73; H2O. 5.10.

1-tert-Butt,1-3-[6-ntethyl-2-(4 piperazin-1-y1) p/tenylamino) pyrido[2,3-dJpyrintidin-7 y1J-urea Using the general procedure by which Example 15 is synthesized, but using the product of Example 135 as the starting material, 1.02 g (100%) of the product (compound 118) is obtained as a solid.
MS (APCI) M+1: Calcd 435.3; Found 435.3.
Anal. Calcd for C-)3H30N8OI=5 HC1=1.75 H-)O:

C. 42.60; H. 5.98; N. 17.28; Cl. 27.34; H-)O, 4.86.
Found: C. 42.03; H. 6.04; N. 16.81: Cl. 22.95: H-) O. 4.72.

1-{2-[4-(cis-3,5-Dimethvl piperazin-1 yl) phenvlaminoJ-6-methyl pvrido[2,3-dJpyrimidin-7 yl}-3-isopropvl-urea Using the general procedure by which Example 33 is synthesized, but using the product of Example 135 as the starting material. along with 4-(4-amino-phenvl)-cis-2.6-dimethvl-piperazine-l-carboxvlic acid tert-butyl ester and isopropylamine as reagents, 0.130 g(100%) of the product (compound 119) is obtained as a solid.
MS (APCI) M+1: Calcd 449.3; Found 449.3.

Anal. Calcd for C24H;2N801 =3 HC1= 1.75 H,)O:

C. 48.90; H, 6.58; N. 19.01; Cl. 16.04; H-)O. 5.35.
Found: C. 49.03; H, 6.63; N. 18.70; Cl. 16.03; H20. 5.19.

1-Cl,clopropyl-3-{2-[4-(cis-3,5-dimeN:yl piperazin-1 yl) phenylaminoJ-6-methvl-pvrido[2,3-dJpvrimidin- 7-yl}-urea Using the general procedure bv which Example 33 is synthesized, but usin~ the product of Example 135 as the starting material, along with 4-(4-amino-phenyl)-cis-2,6-dimethyl-piperazine-l-carboxylic acid tert-butyl ester and cyclopropylamine as reagents, 0.099 g (100%) of the product (compound 120) is obtained as a solid.
MS (APCI) M+1: Calcd 447.3; Found 447.3.
Anal. Calcd for C4H30N801:

C. 49.83; H. 6.19; N. 19.37; C1. 18.39; H20, 3.89.
Found: C, 49.76; H, 6.23; N, 18.92; Cl. 15.66; H20, 3.06.

1-tert-Butyl-3-{2-[4-(cis-3,5-dimetlryl piperazin-1 yl) phenylaminoJ-6-ethvl-pvrido[2,3-dJpyrimidin-7 yl]-urea Using the general procedure by which Example 137 is synthesized, but using (1-cyano-propyl)-phosphonic acid diethyl ester as starting material, 0.34 g (95%) of the product (compound 121) is obtained as a solid.
MS (APCI) M+1: Calcd 477.3: Found 477.3.
Anal. Calcd for C6H26N801 =2.5 HC1=1 H20:

C, 53.26: H, 7.05; N, 19.11: Cl. 15.18; H20. 3.07.
Found: C. 53.63; H. 7.31: N. 18.46: Cl. 15.32: H2O, 3.48.

The following compounds are prepared essentially according to the procedures described in Examples 1-141 and shown in Schemes 1-4:

(a) 1-tert-Butyl-3-[2-(3-chloro-4-piperazin-l-yl-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 2):
(b) 1-tert-Butyl-3-[6-fluoro-2-(4-piperazin-l-vl-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]- urea (compound 3):
(c) 1-{2-[4-(4-Acetyl-piperazin-1-yl)-3-chloro-phenylamino]-pyrido[2.3-d]pyrimidin-7-yl}-3-tert-butyl-urea (compound 6):
(d) 1-{2-[4-(4-Acetyl-piperazin-l-y1)-phenylamino]-6-fluoro-pyrido[2.3-d]pyrimidin-7-yl } -3-tert-butyl-urea (compound 7);
(e) 1-{2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-5-methyl-pyrido[2.3-d]pyrimidin-7-yl}-3-tert-butvl-urea (compound 8):
(f) 1-[2-(3-Chloro-4-piperazin-l-vl-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]-3-cvclohexyl-urea (compound 10);
(g) 1-{2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-pyrido[2.3-d]pyrimidin-7-yl}-3-cyclohexyl-urea (compound 13);
(h) 1-{2-[4-(4-Acetvl-piperazin-1-yl)-3-chloro-phenylamino]-pyrido[2.3-d]pyrimidin-7-yl}-3-cyclohexyl-urea (compound 14):
(i) 1-{2-[4-(4-Acetvl-piperazin-l-yl)-phenylamino]-6-fluoro-pyrido[2.3-d]pyrimidin-7-yl}-3-cyclohexvl-urea (compound 15);
(j) 1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-5-methyl-pyrido[2.3-d]pyrimidin-7-yl}-3-cyclohexyl-urea (compound 16):
(k) 1-(2-Hydroxv-ethyl)-3-[2-(4-piperazin-l-_yl-phem-lamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 17);
(1) 1-[2-(3-Chloro-4-piperazin-l-vl-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]-3-(2-hydroxy-ethyl)-urea (compound 18);
(m) 1-[6-Fluoro-2-(4-piperazin-l-vl)-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]-3-(2-hydroxy-ethyl)-urea (compound 19):
(n) 1-(2-Hydroxy-ethyl)-3-[5-methyl-2-(4-piperazin-l-yl-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 20):

(o) 1-{2-[4-(4-Acetyl-piperazin-l-vl)-phenylamino]-pvrido[2.3-d]pyrimidin-7-yl}-3-(2-hydroxy-ethyl)-urea (compound 21):
(p) 1-{2-[4-(4-Acetyl-piperazin-l-yl)-3-chloro-phenylamino]-pyrido[2.3-d]pyrimidin-7-yl}-3-(2-hydroxy-ethvl)-urea (compound 22):

(q) I-{2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-6-fluoro-pyrido[2.3-d]pyrimidin-7-vl}-3-(2-hydroxy-ethyl)-urea (compound 23):
(r) 1-{2-[4-(4-Acetyl- piperazin-l-yl)-phenylamino]-5 -methvl-pyrido[2.3-d]pyrimidin-7-vl}-3-(2-hydroxv-ethvl)-urea (compound 24):
(s) 1-Ethyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2.3-d]pyrimidin-7-~-1]-urea (compound 25);

(t) 1-[2-(3-Chloro-4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-11]-3-ethyl-urea (compound 26):

(u) 1-Ethvl-3-[6-fluoro-2-(4-piperazin-1-yl-phenylamino)-pyrido[2.3-d]pvrimidin-7-vlJ-urea (compound 27);
(N-) 1-{2-[4-(4-Acet),l-piperazin-l-yl)-phem,lamino]-pyrido[2.3-d]pyrimidin-7-~=1}-3-ethyl-urea (compound 29);
(w) 1-{2-[4-(4-Acetyl-piperazin-l-yl)-3-chloro-phenylamino]-pyrido[2.3-d]pyrimidin-7-yl}-3-ethyl-urea (compound 30):

(x) 1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-6-fluoro-pvrido[2.3-d]pvrimidin-7-~,l}-3-ethyl-urea (compound 31):

(y) 1- { 2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-5-methyl-pvrido[2.3-d]pvrimidin-7-y1}-3-ethvl-urea (compound 32):
(z) 1-tert-Buty l-3-[2-(pyridin-4-ylamino)-pyrido[2.3-d]pyrimidin-7-vl]-urea (compound 33):
(aa) 1-Cyclohexyl-3-[2-(pyridin-4-vlamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 34):

(bb) I-Ethy1-3-[2-(pyridin-4-ylamino)-pvrido[2,3-d]pyrimidin-7-yl]-urea (compound 35):
(cc) 1-(Hydroxy-ethvl)-3-[2-(pvridin-4-vlamino)-pyrido[2.3-d]pyrimidin-7-1-1]-urea (compound 36):
(dd) 1-tert-But~i-3-[6-fluoro-2-(pvridin-4-vlamino)-pyrido[2.3-d]pvrimidin-7- y1]-urea (compound 37):
(ee) 1-Cyclohexyl-3-[6-fluoro-2-(pyridin-4-vlamino)-pyrido[2,3-d]pyrimidin-7-~'1]-urea (compound 38);
(ff) 1-Ethy1-3-[6-fluoro-2-(pyridin-4-vlamino)-pyrido[2.3-d]pvrimidin-7-y1]- urea (compound 39):

(gg) 1-[6-Fluoro-2-(pyridin-4-ylamino)-pyrido[2.3-d]pyrimidin-7-vl]-3-(2-hydroxv-ethyl)-urea (compound 40);
(hh) 1-tert-Butyl-3-[5-methyl-2-(pyridin-4-ylamino)-pyrido[2.3-d]pyrimidin-7- ylj-urea (compound 41);
(ii) 1-Cyclohexyl-3-[5-methyl-2-(pyridin-4-ylamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 42);
(j j ) 1-Ethyl-3-[5-methyl-2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]- urea (compound 43);
(kk) 1-(2-Hydroxy-ethyl)-3-[5-methvl-2-(pyridin-4-vlamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 44);
(11) 1-Cyclohexyl-3-[6-methyl-2-(4-piperazin-l-vI-phenylamino)-pyrido [2.3-d]pyrimidin-7-yl]-urea (compound 54);
(mm) 1-Cyclohexyl-3-[6-cyano-2-(4-piperazin-1-yl-phenylamino)-pyrido [2,3-d]pyrimidin-7-yl]-urea (compound 56);
(nn) 1-Cyclohexyl-3-[6-chloro-2-(4-piperazin-l-yl-phenylamino)-pyrido [2.3-d]pyrimidin-7-yl]-urea (compound 57);
(oo) 1-Cyclohexyl-3-[6-fluoro-5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 58);
(pp) 1-Cyclohexyl-3-[6-bromo-5-methvl-2-(4-piperazin-1-vl-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 59):
(qq) 1-Cyclohexyl-3- [6-chloro-5-methvl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 60);
(rr) I -Isopropyl-3-[5-methvl-2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea (compound 61):
(ss) 1-[5-Methyl-2-(4-piperazin-l-yl-phenylamino)-pyrido[2.3-d]pyrimidin-7-yl]-urea (compound 63):
(tt) 1-(4-Hydroxy-cyclohexyl )-3-[2-(4-piperazin-l-yl-phenylamino)-pyrido [2.3-d]pyrimidin-7-vl]-urea (compound 66);
(uu) 1-(4-Amino-cvclohexyl)-3-[2-(4-piperazin-l-yl-phenylamino)-pyrido [2.3-d]pyrimidin-7-vl]-urea (compound 67):
(vv) l -(2-Dimethvlamino-ethyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido [2.3-d]pyrimidin-7-vl]-urea (compound 68):

(ww) 1-(3-Morpholino-4-yl-propvl)-3-[2-(4-piperazin-l-vl-phenvlamino)-pyrido [2.3-d]pyrimidin-7-yl]-urda (compound 69):
(xx) I -Cyclohexyl-3-[5-methyl-2-(4-piperazin- I -yi-phenylamino)-pyrido [2.3-d]pyrimidin-7-yl]-thiourea (compound 72):
(yy) N-[2-(4-Piperazin-l-vl-phenylamino)-pyrido[2.3-d]pyrimidin-.
7-vl]-acetamide (compound 73);
(zz) 4-[7-(3-Cyclohexyl-ureido)-pyrido[2,3-d]pyrimidin-2-vlamino]-benzenesulfonamide (compound 74);
(aaa) 1-Cyclohexyl-3- { 2-[4-(1-piperazin-l-yl-methanovl)-phenylamino]-pvrido[2,3-d]pyrimidin-7-yl}-urea (compound 75):
(bbb) 1-Cyclohexyl-3-[2-(4-fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-vl]-urea (compound 76):
(ccc) 1-(2-{4-[4-(2-Amino-4-methyl-pentanoyl)-piperazin-1-yl]-phenylamino}-pyrido[2.3-d]pyrimidin-7-yl)-3-cvclohexyl-urea (bompound 77);
and (ddd) 1-(2-{4-[4-(2-Amino-)-methyl-butanoyl)-piperazin-1-yl]-phenylamino}-pyrido[2,3-d]pyrimidin-7-vl)-3-cyclohexyl-urea (compound 78).

Biological AssRt-As noted above. the compounds of this invention are potent inhibitors of cdks. and accordinaly, are useful in treatinsz and preventing atherosclerosis and other cell proliferative disorders like cancer that are mediated by such cdk enzymes. The compounds exhibit excellent inhibitotv activitv against a number of cdk enzvmes, including cdkcdkl/cyclinB. cdk2/cyclinA. cdk2/cvclinE, and cdk4/cvclinD. when evaluated in standard assays routinelv utilized by those skilled in the art to measure cdk inhibitorv activities. Typical assays are carried out as follows.

Ct-clin Dependent 1-inase 4(cdk4) Assa}-Enzvme assays for IC50 determinations and kinetic evaluation are performed in 96-well filter plates (Millipore MADVN6550). The total volume is 0.1 mL containine a final concentration of 20 mM TRIS

* Trade-mark (tris[hydroxymethyl]aminomethane). at pH 7.4. 50 mM NaCI. 1 mM
dithiothreitol. 10 mM MgCI~. 25 M ATP containing 0.25 Ci of [~2P]ATP, 20 ng of cdk4. 1 g of retinoblastoma. and appropriate dilutions of a compound of the present invention. All components except the ATP are added to the wells. and the plate is placed on a plate mixer for 2 minutes. The reaction is started by adding ['2P]ATP, and the plate is incubated at 25 C for 15 minutes. The reaction is terminated bv addition of 0.1 mL of 20% trichloroacetic acid (TCA). The plate is kept at 4 C for at least 1 hour to allo,.v the substrate to precipitate. The '%vells are then ~vvashed 5 times xvith 0.2 mL of 10% TCA and 32P incorporation is determined with a beta plate counter (Wallac Inc.. Gaithersburg, MD).
Cvclin Dependent liinase 1 and 2 Assavs (cdk1/chclinB, cdk2/cti'clinA, cdk2/cyclinE) Enzyme assays for IC50 determinations and kinetic evaluation are performed in a 96-well filter plate (Millipore MADVN6550) in a total volume of 0.1 mL of 20 mM TRIS (tris[hydroxymethyl]aminomethane), at pH 7.4, 50 mM

NaCl. 1 mM dithiothreitol, 10 mM MgC12, 12 mM ATP containina 0.25 Ci of p3 2P]ATP. 20 ng of enzyme (either cdkl/B. cdk2/A, or cdk2E). 1 g retinoblastoma, and appropriate dilutions of the particular invention compound.
All components except the ATP are added to the wells. and the plate is placed on a plate mixer for 2 minutes. The reaction is begun by addition of ['2P]ATP, and the plate is incubated at 25 C for 15 minutes. The reaction is terminated by addition of 0.1 mL of 20% TCA. The plate is kept at 4 C for at least 1 hour to allow the substrate to precipitate. The rells are then washed 5 times with 0.2 mL of 10%
TCA and'2P incorporation determined with a beta plate counter ( 'allac Inc., Gaithersburg. MD).

Ct'clin Dependent Kinase 5/p25 Proline-directed Protein hinaseAssa}, Source of enzvme: recombinant baculovirus-infected insect cell sf'9-expressed recombinant cdk5-p25 complex.

Purpose: To evaluate the ability of test agents to inhibit cdk5/p25 phosphorylation of Histone H I.
Method: Baculovirus-insect cell His-tagged cdk5/Glu-tagged p25 (or GST-p25) enzvme complex is diluted to a concentration of 50 na/20 L in Enzyme Dilution Buffer (EDB - 50 mM Tris-HCI [pH 8.0], 10 mM NaC1, 10 mM
MaC12. and 1 mM DTT). A 20 L sample of test agent (diluted in EDB) is then combined -,vith 20 L of the of the final cdk5/p25 enzyme preparation and allowed to stand for 5 minutes at room temperature. Twentv-five microliters of substrate solution containinEi 115 L/mL Histone H1, 30 M ATP (vanadate-free), and 30 Ci/mL y->;P ATP (Amersham) in EDB is then added to the test agent/enzyme preparation and shaken at 30 C for 45 minutes. A 50 L sample of the final preparation is added to 100 mL of 150 mM phosphoric acid on ice for 30 minutes to facilitate precipitation. The precipitate is then filtered through a 96-well phosphocellulose filter plate and subsequently rinsed 3 times with 75 mM

phosphoric acid. Each well then receives 20 L of scintillation cocktail, and the plates are counted for beta emissions using a Trilux Counter (33P filter protocol).
Test samples are compared to Control (no test aaent present: as 0% inhibition) and Baseline level (no enzyme, no test agent: as 100 /o inhibition) beta emissions to determine the percent inhibition of Histone H 1 phosphorvlation.
The results of the foreQoing assays for representative invention compounds are presented in Table 2 below. The invention compounds exhibit IC50 values ranging from 0.027 N1 to >5 M against cdk 1/B, from 0.010 M to >5 M
against cdk2/A, from 0.020 to >5 M against cdk2/E, and from 0.004 to >5 M
against cdk4/D. The most potent compound overall is compound 9, which exhibits IC50 values of 0.027 M. 0.0 10 M. 0.020 M, 0.005 M, against cdkl/B, cdk2A. cdk2E. and cdk4D, respectivelv.

TABLE 2. Inhibition of Cdks: IC50 ( M) Compound Cdkl/B Cdk2/A Cd1:2/E Cdk4D
1 0.219 0.060 0.130 0.006 4 >5 >5 >5 1.5 0.463 0.130 0.130 0.037 9 0.027 0.010 0.020 0.005 11 0.159 0.092 0.125 0.011 12 >5 >5 >5 2.100 28 >5 >5 >5 >5 45 0.552 0.054 0.110 0.045 46 0.075 0.300 >5 47 >5 >5 >5 >5 48 0.257 0.113 0.098 0.018 49 0.911 0.528 0.475 0.050 50 0.069 0.022 0.035 0.007 51 0.053 0.024 0.030 0.004 52 0.472 0.213) 0.126 0.027 53 >5 >5 >5 >5 TABLE 2. Inhibition of Cdks; IC50 ( M) (cont) Compound Cdkl/B Cdk2/A Cdk2/E Cdk4D
55 >5 >5 >5 0.300 64 >5 >5 >5 >5 65 >5 >5 >5 >5 70 1.448 0.697 0.530 0.017 71 >5 >5 >5 >5 79 >5 1.066 >5 >5 80 0.461 0.092 0.230 0.460 81 2.610 1.560 3.250 0.500 g3 0.399 0.305 0.315 0.055 84 >5 >5 >5 >5 85 >5 >5 >5 >5 86 >5 >5 >5 >5 87 >5 >5 >5 >5 88 0.418 0.043 0.055 0.025 89 >5 >5 >5 >5 91 >5 >5 >5 0.070 93 >5 >5 >5 >5 94 >5 0.101 95 >5 0.310 96 6.365 1.108 1.550 >5 97 0.862 0.278 0.345 >5 TABLE 2. Inhibition of Cdks: IC50 ( M) (cont) Compound Cdkl/B Cdk2/A Cdl?/E Cdk4D
98 0.442 0.157 0.140 1.050 99 1.810 1.012 0.410 >5 100 0.265 0.153 0.415 0.035 102 3.130 3.590 4.500 0.165 103 >5 >5 >5 >5 104 >5 >5 >5 0.185 106 0.350 0.440 107 1.728 1.950 1.650 0.019 108 2.425 2.035 3.050 0.067 111 >5 >5 >5 >5 113 >5 >5 >5 3.000 114 >5 >5 >5 >5 115 0.094 0.022 0.051 0.007 116 >5 >5 3.750 0.313 117 >5 >5 4.000 0.076 118 >5 >5 3.800 0.079 119 >5 >5 >5 1.600 120 >5 >5 >5 1.900 121 >5 >5 >5 0.092 The compounds of this invention also are inhibitors of the growth factor receptor tyrosine kinase enzymes. FGFr and PDGFr. and of the nonreceptor tvrosine kinase enzvme. c-Src. Several of the invention compounds have been evaluated via standard assays that measure their ability to inhibit tNrosine kinase enzymes. These assays are carried out as follows:

PDGFand FGF Receptor Tvrosine hinaseAssqtis Full-length cDNAs for the mouse PDGF-0 and human FGF-1 (fle) receptor tyrosine kinases are obtained from J. Escobedo and prepared as described in.J. Biol. Chem.. 1991:262:1482-1487. PCR primers are designed to amplify a fraament of DNA that codes for the intracellular tvrosine kinase domain. The fraRment is inserted into a baculovirus vector. cotransfected =ith AcNINPV
DNA.
and the recombinant virus isolated. SF9 insect cells are infected with the virus to overexpress the protein, and the cell lysate is used for the assay. Assays are performed in 96-well plates (100 L/incubation/well), and conditions are optimized to measure the incorporation of 32P from y32P-ATP into aQlutamate-tyrosine co-polymer substrate. Briefly, to each well is added 82.5t L of incubation buffer containing 25 mM Hepes (pH 7.0). 150 mM NaCI. 0.1% Triton .X-100, 0.2 mM PMSF 0.2 mM Na3VO:}. 10 mM MnCI-). and 750 g/mL of Poly (4:1) glutamate-tyrosine followed by 2.5 L of inhibitor and 5 L of enzyme lysate (7.5 g/ L FGF-TK or 6.0 g/ L PDGF-TK) to initiate the reaction. Following a 10-minute incubation at 25 C. 10 mL of y3'P-ATP (0.4 Ci plus 50 M ATP) is added to each well. and samples are incubated for an additional 10 minutes at 25 C. The reaction is terminated by the.addition of-100 L of 30%
trichloroacetic acid (TCA) cdntaining 20 mM sodium pvrophosphate and precipitation of material onto glass fiber mats (Wallac). Filters are washed 3 times with 15%
TCA
containing 100 mM sodium pyrophosphate. and the radioactivity retained on the filters counted in a Wallac 1250 Betaplate reader. Nonspecific activity is defined as radioactivitv retained on the filters following incubation of samples with buffer alone (no enzyme). Specific enzymatic activity (enzyme plus buffer) is defined as total activity minus nonspecific activity. The % inhibition at 50 M is determined.
and for the more potent compounds the concentration of the compound that inhibited specific activitv by 50% (IC50) is determined based on the inhibition curve.

* Trade-mark C-Src kinaseAssaY
C-Src kinase is purified from baculovirus infected insect cell lysates using an antipeptide monoclonal antibody directed against the N-terminal amino acids (amino acids 2-17) of c-Src. The antibody. covalentlv linked to 0.65 um latex beads. is added to a suspension of insect cell lysis buffer comprised of 150 mM
NaCI. 50 mM Tris pH 7.5, 1 mM DTT, 1% NP-40. 2 mM EGTA. 1 mM sodium vanadate. 1 mM PMSF, 1 ug/mL each of leupeptin. pepstatin, and aprotinin.
Insect cell lysate containing c-Src protein is incubated with these beads for 3 to 4 hours at 4 C ,vith rotation. At the end of the lvsate incubation, the beads are rinsed 3 times in lvsis buffer. resuspended in lysis buffer containina 10% glycerol, and frozen. These latex beads are thawed, rinsed 3 times in assay buffer (40 mM
Tris.
pH 7.5, 5 mM MgC12), and suspended in the same buffer. In a Millipore 96-well plate with a 0.65 um polyvinylidine membrane bottom are added the reaction components: 10 uL c-Src beads. 10 uL of 2.5 mg/mL poly GluTyr substrate, 5 uM

ATP containing 0.2 uCi labeled 32P-ATP. 5 uL DMSO containing inhibitors or as a solvent control. and buffer to make the final volume 125 uL. The reaction is started at room temperature by addition of the ATP and quenched 10 minutes later by the addition of 125 uL of 30% TCA. 0.1 M sodium pyrophosphate for 5 minutes on ice. The plate is then filtered and the wells washed with two 250-mL
aliquots of 15% TCA. 0.1 M pyrophosphate. The filters are then punched.
counted in a liquid scintillation counter. and the data examined for inhibitory activity in comparison to a knovN,n inhibitor such as erbstatin. The method is also described in J. Med. Chem., 1994:37:598-609.
The tyrosine kinase inhibitorv activity for representative invention compounds evaluated in the foregoin' assays is P-iven in Table 3 .

TABLE 3. Inhibition of Tvrosine Kinases; % Inhibition at 50 N1 (IC50 [ M] in parenthesis if determined) Compound PDGFr FGFr 1 94.4 (0.593) 93.7 9 89.8 11 (0.131) (0.284) 45 21.9 67.4 46 17.5 19.5 47 10.5 55 (0.033) (0.151) 70 (0.536) (1.15) 80 18.6 117 (0.081) (0.061) As noted above, the invention also provides pharmaceutical compositions comprising an invention compound admixed with a carrier, diluent, or excipient.
The following examples illustrate typical compositions provided by this invention.

A pharmaceutical compositions in the form of hard gelatin capsules for oral administration is prepared using the folloxving inaredients:

Quantity (mg/capsule) Active compound 250 Starch powder 200 Maiinesium stearate 10 Total 460 The above ingredients are mixed and filled into hard gelatin capsules in 460 mg quantities. A typical active ingredient is 1-isobutyl-3-[2-{(2-chloro-4-piperazin-l-yl)-phenylamino; -pyrido[2.3-d]pyrimidin-7-yl]-urea. The composition is administered from 2 to 4 times a day for treatment of postsurgical restenosis.

EXAMPLE 144a Compositions for Oral Suspension Ingredient Amount 1-Isopropvl-3-[5-methvl-6-bromo-2-(3-ethylp~,ridin-4- 500 mg ylamino}-pvrido-[2.3-d]pyrimidin-7-yl]-urea Sorbitol solution (70% NF) 40 mL
Sodium benzoate 150 ma Saccharin 10 mg Chem flavor 50 mg Distilled water q.s. ad 100 mL

The sorbitol solution is added to 40 mL of distilled water. and the pvridopyrimidine is suspended therein. The saccharin. sodium benzoate. and flavorina are added and dissolved. The volume is adjusted to 100 mL with distilled water. Each milliliter of syrup contains 5 mg of active ingredient.
EXAMPLE 144b Tablets Each Containina 60 ma of Active Ingredient Active inaredient 60 m2 Starch -1 ~ mg Microcrvstalline cellulose mg Polvvinylpyrrolidone (as 10% solution in ~vater) 4 mg Sodium carboxymethvl starch 4.5 mg Magnesium stearate 0.5 mg Talc 1.0 mg Total 1 -50 mg The active in7redient. starch. and cellulose are passed through a No. 45 mesh US sieve and mixed thorouahlv. The solution of polyvinylpyrrolidone is mixed with the resultant powders and then passed throuvh a No. 14 mesh US

sieve. The granules are dried at 50 C to 60 C and passed through a No. 18 mesh US sieve. The sodium carboxvmethvl starch. maUnesium stearate. and talc, previously passed through a No. 60 mesh US sieve, are then added to the granules which, after mixing, are compressed on a tablet machine to yield tablets each weighing 150 mg.
A typical active ingredient utilized in the above preparation is the compound of Example 40 (Compound 12). This composition is well-suited to treatment of diabetic retinopathy.

EXAMPLE 144c A parenteral composition suitable for administration by injection is prepared by dissolving 100 mg of compound 77 in 250 mL of 0.9% aqueous sodium chloride solution and adjusting the pH of the solution to about 7Ø
This formulation is 'ell-suited for the treatment of breast cancer.
EXAMPLE 144d Preparation for Suppositories A mixture of 500 mg of 1-n-butyl-3-[2-(4-piperazin-l-yl-phenylamino)-pvrido[2.3-d]p~,rimidin-7-vl]-urea and 1500 mg of theobroma oil are blended to uniformitv at 60 C. The mixture is cooled to 24 C in tapered molds. Each suppositon, will weigh about 2 g and can be administered from I to 2 times each day for treatment of viral infections such as herpes and HIV.

EXAMPLE 144e Topical Preparation Inaredient Amount (mg) 1-Cycloheavl-3- { [2-(4-morpholin-l-yl-phenvlamino)]-5,6- 20 difluoro-pyrido[2,3-d]pyrimidin-7-yl } -urea Propylene glycol 100 White Petrolatum 500 Cetearvl alcohol 50 Glvicervl stearate 100 PEG 100 stearate 100 Ceteth-20 50 Monobasic sodium phosphate 80 Total 1000 The invention compound is blended to uniformitv with the other ingredients to make a thick suspension. The suspension is applied evenly to an adhesive backed polymeric film and cut into a 2-inch square. The patch is applied to the skin of a patient suffering from psoriasis.
EXAMPLE 144f Slow Release Preparation Five hundred milligrams of 7-acetamido-6-bromo-2-[4-(2-diethylaminoethoay)-phenylamino]pyrido[2.3-d]pyrimidine hydrochloride was placed in an osmotic pump tablet and administered orally to a subject for treatment and prevention of restenosis.
The invention and the manner and process of making and using it are now described in such full. clear. concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same. It is to be understood that the foregoiny describes preferred embodiments of the present invention, and that modifications may be made therein without departing from the spirit or scope of the present invention as set forth in the claims. To particularly point out and distinctly claim the subject matter regarded as the invention, the following claims conclude this specification.

Claims

CLAIMS:

1. A compound of the Formula I

and pharmaceutically acceptable salts, C1-C6 alkyl esters, C5-C7 cycloalkyl esters, arylalkyl esters, C1-C6 alkyl amines and secondary C1-C6 dialkyl amines thereof, wherein:

R2, R7, R13, R14, and R15 are independently hydrogen, or lower alkyl, lower alkenyl, or lower alkynyl, each of which is optionally substituted with up to 5 groups independently selected from the group consisting of halogen, cyano, nitro, -R9, -NR9R10, -OR9, -(CH2)n CO2R9, -(CH2)n SO2R11, -(CH2)n R11, -COR9, -CONR9R10, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, -NR9SO2R10, and a 5-7 membered heterocycle having 1 to 4 heteroatoms selected from N, O or S optionally substituted with up to 3 groups independently selected from the group consisting of -R9, -NR9R10, -OR9, -NR9COR10, -COR10, -(CH2)n SO2R11, and -(CH2)n R11, or -(CH2)n R12 optionally substituted with up to 5 groups independently selected from the group consisting of halogen, cyano, nitro, -R9, -NR9R10, -OR9, -(CH2)n CO2R9, -(CH2)n SO2R(CH2)nR11, -COR9, -CONR9R10, -SO3R9, SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, -NR9SO2R10, and a 5-7 membered heterocycle having 1 to 4 heteroatoms selected from N, O or S optionally substituted with up to 3 groups independently selected from the group consisting of -R9, -NR9R10, -OR9, -NR9COR10, -COR10, -(CH2)n SO2R11, and -(CH2)n R11;

R5 is halogen, cyano, nitro, -R9, -NR9R10, or -OR9;

R6 is halogen, cyano, nitro, -R9, -NR9R10, -OR9, -CO2R9, -COR9, -CONR9R10, -NR9COR10, -SO2NR9R10, -SO2R9, -SR9, -P03R9R10, -POR9R10, -PO(NR9R10)2, or lower alkenyl or lower alkynyl optionally substituted with -R9;

R8 is H, -CO2R13, -COR13, -CONR13R14, -CSNR13R14, -C(NR13)NR14R15, -SO3R13, -SO2R13, -SO2NR13R14, -PO3R13R14, -POR13R14, -PO(NR13R14)2;
R9 and R10 are independently hydrogen, or lower alkyl, optionally substituted with up to 3 groups selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy and phenyl, or when taken together with the nitrogen to which they are attached, R9 and R10 form a ring having from 3-7 members, up to four of which may be selected from the group consisting of O, S, and NR20, where R20 is hydrogen, lower alkyl, or -CO lower alkyl;

R11 is a 5-7 membered heteroaryl or heterocyclic group having 1 to 4 heteroatoms selected from N, O or S;

R12 is a C3-C7 cycloalkyl, a single or multiple ringed aryl or a 5-7 membered heteroaryl or heterocyclic group having 1 to 4 heteroatoms selected from N, O or S; and n is 0, 1, 2, or 3.

2. A compound of the Formula II

and pharmaceutically acceptable salts, C1-C6 alkyl esters, C5-C7 cycloalkyl esters, arylalkyl esters, C1-C6 alkyl amines and secondary C1-C6 dialkyl amines thereof, wherein:

R7, R13, R14, and R15 are independently hydrogen, or lower alkyl, lower alkenyl, or lower alkynyl, each of which is optionally substituted with up to 5 groups independently selected from the group consisting of halogen, cyano, nitro, -R9, -NR9R10, -OR9, - (CH2)n CO2R9, - (CH2)n SO2R11, -(CH2)n R11, -COR9, -CONR9R10, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, -NR9SO2R10, and a 5-7 membered heterocycle having 1 to 4 heteroatoms selected from N, O or S optionally substituted with up to 3 groups independently selected from the group consisting of -R9, -NR9R10, -OR9, -(CH2)n SO2R11, -(CH2)n R11, or -(CH2)n R12 optionally substituted with up to 5 groups independently selected from the group consisting of halogen, cyano, nitro, -R9, -NR9R10, -OR9, -(CH2)n CO2R9, -(CH2)n SO2R11, -(CH2)n R11, -COR9, -CONR9R10, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, -NR9SO2R10, and a 5-7 membered heterocycle having 1 to 4 heteroatoms selected from N, O or S optionally substituted with up to 3 groups independently selected from the group consisting of -R9, -NR9R10, -OR9, -(CH2)n SO2R11, -(CH2)n R11;

R5 is halogen, cyano, nitro, -R9, -NR9R10, or -OR9;

R6 is halogen, cyano, nitro, -R9, -NR9R10, -OR9, -CO2R9, -COR9, -CONR9R10, -NR9COR10, or lower alkenyl or lower alkynyl optionally substituted with -R9;

R8 is H, -CO2R13, -COR13, -CONR13R14, -CSNR13R14, -C(NR13)NR19R15, -SO3R13, -SO2R13, -SO2NR13R14, -PO3R13R14, -POR13R14, -PO(NR13R14)2;
R9 and R10 are independently hydrogen, or lower alkyl, optionally substituted with up to 3 groups selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy and phenyl, or when taken together with the nitrogen to which they are attached, R9 and R10 form a ring having from 3-7 members, up to four of which may be selected from the group consisting of O, S, and NR20, where R20 is hydrogen, lower alkyl, or -CO lower alkyl;

R11 is a 5-7 membered heteroaryl or heterocyclic group having 1 to 4 heteroatoms selected from N, O or S;

R12 is a C3-C7 cycloalkyl, a single or multiple ringed aryl or a 5-7 membered heteroaryl or heterocyclic group having 1 to 4 heteroatoms selected from N, O or S; and n is 0, 1, 2, or 3; and R16, R17 , and R18 are independently hydrogen, halogen, amino, mono- or dialkylamino, hydroxy, lower alkyl, lower alkoxy, cyano, nitro, carboxy, carboxyalkyl, aminocarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyl, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, or -NR9SO2R10; or R16 is a carbocyclic group containing from 3-7 members, up to 2 of which members are heteroatoms selected from oxygen and nitrogen, wherein the carbocyclic group is unsubstituted or substituted with 1, 2, or 3 groups independently selected from the group consisting of halogen, hydroxy, lower alkyl, trifluoromethyl, lower alkoxy, amino, mono- or dialkylamino, single or multiple ringed aryl, 5-7 membered heteroaryl group having 1 to 4 heteroatoms selected from N, O or S, arylalkyl, heteroarylalkyl, heteroarylsulfonyl, heteroarylsulfonylalkyl, heterocyclylalkyl, heterocyclylsulfonyl, and heterocyclylsulfonylalkyl.

3. A compound of the Formula III

and pharmaceutically acceptable salts, C1-C6 alkyl esters, C5-C7 cycloalkyl esters, arylalkyl esters, C1-C6 alkyl amines and secondary C1-C6 dialkyl amines thereof, wherein:

R2 is hydrogen, or lower alkyl, lower alkenyl, or lower alkynyl, each of which is optionally substituted with up to 5 groups independently selected from the group consisting of halogen, cyano, nitro, -R9, -NR9R10, -OR9, - (CH2) CO2R9, - (CH2)SO2R11, -(CH2)n R11, -COR9, -CONR9R10, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, -NR9SO2R10, and a 5-7 membered heterocycle having 1 to 4 heteroatoms selected from N, O or S optionally substituted with up to 3 groups independently selected from the group consisting of -R9, -NR9R10, -OR9, -(CH2)n SO2R11, and -(CH2)n R11, or -(CH2)n R12 optionally substituted with up to 5 groups independently selected from the group consisting of halogen, cyano, nitro, -R9, -NR9R10, -OR9, -(CH2)n CO2R9, -(CH2)n SO2R11, -(CH2)n R11, -COR9, -CONR9R10, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, -NR9SO2R10, and a 5-7 membered heterocycle having 1 to 4 heteroatoms selected from N, O or S optionally substituted with up to 3 groups independently selected from the group consisting of -R9, -NR9R10, -OR9, -(CH2)n SO2R11, - (CH2)n R11-R5 is halogen, cyano, nitro, -R9, -NR9R10, or -OR9;

R6 is halogen, cyano, nitro, -R9, -NR9R10, -OR9, -CO2R9, -COR9, -CONR9R10, -NR9COR10, -SO2NR9R10, -SO2R9, -SO3R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, or lower alkenyl or lower alkynyl optionally substituted with -R9;

R9 and R10 are independently hydrogen, or lower alkyl, optionally substituted with up to 3 groups selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy, or phenyl, or when taken together with the nitrogen to which they are attached, R9 and R10 form a ring having from 3-7 members, up to four of which may be selected from the group consisting of , O, S, and NR20, where R20 is hydrogen, lower alkyl, or -CO lower alkyl;

R11 is a 5-7 membered heteroaryl or heterocyclic group having 1 to 4 heteroatoms selected from N, O or S;

R12 is a C3-C7 cycloalkyl, a single or multiple ringed aryl or a 5-7 membered heteroaryl or heterocyclic group having 1 to 4 heteroatoms selected from N, O or S; and n is 0, 1, 2, or 3; and R19 is hydrogen, or lower alkyl, lower alkenyl, or lower alkynyl, each of which is optionally substituted with up to 5 groups independently selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy, cyano, nitro, carboxy, carboxyalkyl, aminocarbonyl, mono- or dialkylaminocarbonyl, lower alkylcarbonyl, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, and -NR9SO2R10, or single or multiple ringed aryl, heteroaryl, single or multiple ringed arylalkyl, heteroarylalkyl, C3-C7 cycloalkyl or C3-C7 cycloalkyl-alkyl, where each aryl, heteroaryl or cycloalkyl group is optionally substituted with up to 5 groups independently selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy, cyano, nitro, carboxy, carboxyalkyl, aminocarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyl, -SO3R9, -SO2R9R10, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, and -NR9SO2R10, or a(CH2)n- carbocyclic group containing from 3-7 members, up to 2 of which members are heteroatoms selected from oxygen and nitrogen, wherein the carbocyclic group is unsubstituted or substituted with 1, 2, or 3 groups independently selected from the group consisting of halogen, hydroxy, lower alkyl, trifluoromethyl, lower alkoxy, amino, mono- or dialkylamino, single or multiple ringed aryl, 5-7 membered heteroaryl group having 1 to 4 heteroatoms selected from N, O or S, arylalkyl, heteroarylalkyl, heteroarylsulfonyl, heteroarylsulfonylalkyl, heterocyclylalkyl, heterocyclylsulfonyl, and heterocyclylsulfonylalkyl; and R21 is hydrogen, lower alkyl, or lower alkyl substituted with phenyl.

4. A compound of the Formula IV

and pharmaceutically acceptable salts, C1-C6 alkyl esters, C5-C7 cycloalkyl esters, arylalkyl esters, C1-C6 alkyl amines and secondary C1-C6 dialkyl amines thereof, wherein:

R5 is halogen, cyano, nitro, -R9, -NR9R10, or -OR9;

R6 is halogen, cyano, nitro, -R9, -NR9R10, -OR9, -Co2R9, -COR9, -CONR9R10, -NR9COR10, -SO2R9R10, -SO2R9, -SO3R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, or lower alkenyl or lower alkynyl optionally substituted with -R9;

R9 and R10 are independently hydrogen, or lower alkyl optionally substituted with up to 3 groups selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy and phenyl, or when taken together with the nitrogen to which they are attached, R9 and R10 form a ring having from 3-7 members, up to four of which may be selected from the group consisting of , O, S, and NR20, where R20 is hydrogen, lower alkyl, or -CO lower alkyl;

R11 is a 5-7 membered heteroaryl or heterocyclic group having 1 to 4 heteroatoms selected from N, 0 or S;

R16, R17, and R18 are independently selected from the group consisting of halogen, cyano, nitro, -R9, -NR9R10, -OR9, - (CH2)n CO2R9, - (CH2)n SO2R11, - (CH2)n R11, -COR9, -CONR9R10, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, -NR9SO2R10, and a 5-7 membered heterocycle having 1 to 4 heteroatoms selected from N, O or S optionally substituted with up to 3 groups independently selected from the group consisting of -R9, -NR9R10, -OR9, -NR9COR10, -COR10, - (CH2)n SO2R11, and - (CH2)n R11;
R19 is hydrogen, or lower alkyl, lower alkenyl, or lower alkynyl, each of which is optionally substituted with up to 5 groups independently selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy, cyano, nitro, carboxy, carboxyalkyl, aminocarbonyl, mono- or dialkylaminocarbonyl, lower alkylcarbonyl, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, and -NR9SO2R10, or single or multiple ringed aryl, 5-7 membered heteroaryl group having 1 to 4 heteroatoms selected from N, O
or S, arylalkyl, heteroarylalkyl, C3-C7 cycloalkyl or C3-C7 cycloalkyl-alkyl, where each aryl, heteroaryl or cycloalkyl group is optionally substituted with up to 5 groups independently selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy, cyano, nitro, carboxy, carboxyalkyl, aminocarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyl, -SO3R9, -SO2R9R10, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, and -NR9SO2R10, or a(CH2)n- carbocyclic group containing from 3-7 members, up to 2 of which members are heteroatoms selected from oxygen and nitrogen, wherein the carbocyclic group is unsubstituted or substituted with 1, 2, or 3 groups independently selected from the group consisting of halogen, hydroxy, lower alkyl, trifluoromethyl, lower alkoxy, amino, mono- or dialkylamino, single or multiple ringed aryl, 5-7 membered heteroaryl group having 1 to 4 heteroatoms selected from N, O or S, arylalkyl, heteroarylalkyl, heteroarylsulfonyl, heteroarylsulfonylalkyl, heterocyclylalkyl, heterocyclylsulfonyl, and heterocyclylsulfonylalkyl; and R21 is hydrogen, lower alkyl, or lower alkyl substituted with phenyl.

5. A compound of the Formula V

and the pharmaceutically acceptable salts, C1-C6 alkyl esters, C5-C7 cycloalkyl esters, arylalkyl esters, C1-C6 alkyl amines and secondary C1-C6 dialkyl amines thereof, wherein:
R5 is halogen, cyano, nitro, -R9, -NR9R10, or -OR9;

R6 is halogen, cyano, nitro, -R9, -NR9R10, -OR9, -CO2R9, -COR9, -CONR9R10, -NR9COR10, -SO2NR9R10, -SO2R9, -SO3R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, or lower alkenyl or lower alkynyl optionally substituted with -R9;

R16, R17, and R18 are independently selected from the group consisting of hydrogen, halogen, cyano, nitro, -R9, -NR9R10, -OR9, -(CH2)n CO2R9, -(CH2)n SO2R11, - (CH2)n R11, -COR9, -CONR9R10, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, and -NR9SO2R10, or a 5-7 membered heterocycle having 1 to 4 heteroatoms selected from N, O or S optionally substituted with up to 3 groups independently selected from the group consisting of -R9, -NR9R10, -OR9, -NR9COR10, -COR10, -(CH2)n SO2R11, and -(CH2)n R11;

R9 and R10 are independently hydrogen, or lower alkyl optionally substituted with up to 3 groups selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy and phenyl, or when taken together with the nitrogen to which they are attached, R9 and R10 form a ring having from 3-7 members, up to four of which may be selected from the group consisting of , O, S, and NR20, where R20 is hydrogen, lower alkyl, or -CO lower alkyl;

R11 is a 5-7 membered heteroaryl or heterocyclic group having 1 to 4 heteroatoms selected from N, O or S;

R19 is hydrogen, or lower alkyl, lower alkenyl, or lower alkynyl, each of which is optionally substituted with up to 5 groups independently selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy, cyano, nitro, carboxy, carboxyalkyl, aminocarbonyl, mono- or dialkylaminocarbonyl, lower alkylcarbonyl, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO(NR9R10)2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, and -NR9SO2R10, or single or multiple ringed aryl, 5-7 membered heteroaryl group having 1 to 4 heteroatoms selected from N, O
or S, arylalkyl, heteroarylalkyl, C3-C7 cycloalkyl or C3-C7 cycloalkyl-alkyl, where each aryl, heteroaryl or cycloalkyl group is optionally substituted with up to 5 groups independently selected from the group consisting of halogen, amino, mono- or dialkylamino, hydroxy, lower alkoxy, cyano, nitro, carboxy, carboxyalkyl, aminocarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyl, -SO3R9, -SO2R9R10, -SO2NR9R10, -SO2R9, -SR9, -P03R9R10, -POR9R10, -PO (NR9R10) 2, -NR9COR10, -NR9CO210, -NR9CONR9R10, and -NR9SO2R10, or a(CH2)n- carbocyclic group containing from 3-7 members, up to 2 of which members are heteroatoms selected from oxygen and nitrogen, wherein the carbocyclic group is unsubstituted or substituted with 1, 2, or 3 groups independently selected from the group consisting of halogen, hydroxy, lower alkyl, trifluoromethyl, lower alkoxy, amino, mono- or dialkylamino, single or multiple ringed aryl, 5-7 membered heteroaryl group having 1 to 4 heteroatoms selected from N, O or S, arylalkyl, heteroarylalkyl, heteroarylsulfonyl, heteroarylsulfonylalkyl, heterocyclylalkyl, heterocyclylsulfonyl, and heterocyclylsulfonylalkyl; and R21 is hydrogen, lower alkyl, or lower alkyl substituted with phenyl.

6. A compound of Formula VI
and the pharmaceutically acceptable salts, C1-C6 alkyl esters, C5-C7 cycloalkyl esters, arylalkyl esters, C1-C6 alkyl amines and secondary C1-C6 dialkyl amines thereof, wherein:

R5 is halogen, cyano, nitro, -R9, -NR9R10, or -OR9;

R6 is halogen, cyano, nitro, -R9, -NR9R10, -OR9, -CO2R9, -COR9, -CONR9R10, -NR9COR10, -SO2NR9R10, -SO2R9, -SO3R9, -SR9, -PO3R9R10, -POR9R10, -PO (NR9R10) 2 , or lower alkenyl or lower alkynyl optionally substituted with -R9;

R17 and R18 are independently selected from the group consisting of halogen, cyano, nitro, -R9, -NR9R10, -OR9, - (CH2) CO2R9, - (CH2) n SO2R11, - (CH2) n R11, -COR9, -CONR9R10, -SO3R9, -SO2NR9R10, -SO2R9, -SR9, -PO3R9R10, -POR9R10, -PO (NR9R10) 2, -NR9COR10, -NR9CO2R10, -NR9CONR9R10, and -NR9SO2R10, or a 5-7 membered heterocycle having 1 to 4 heteroatoms selected from N, O or S optionally substituted with up to 3 groups independently selected from the group consisting of -R9, -NR9R10, -OR9, -NR9COR10, -COR10, - (CH2) n SO2R11, and - (CH2) n R11;

R9, R10 and R11 are as defined in claim 1; and R22 and R23 independently are hydrogen or alkyl.

7. A compound selected from:
1-tert-Butyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-tert-Butyl-3-[2-(3-chloro-4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-tert-Butyl-3-[6-fluoro-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-tert-Butyl-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-tert-butyl-urea;
1-{2-[4-(4-Acetyl-piperazin-1-yl)-3-chloro-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-tert-butyl-urea;
1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-3-tert-butyl-urea;
1-{2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-5-methyl-pyrido[2,3-d]pyrimidin-7-yl}-3-tert-butyl-urea;
1-Cyclohexyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-[2-(3-Chloro-4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-cyclohexyl-urea;
1-Cyclohexyl-3-[6-fluoro-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[5-methyl-2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-{2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-cyclohexyl-urea;
1-{2-[4-(4-Acetyl-piperazin-l-yl)-3-chloro-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-cyclohexyl-urea;
1-{2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-3-cyclohexyl-urea;
1-{2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-5-methyl-pyrido[2,3-d]pyrimidin-7-yl}-3-cyclohexyl-urea;
1-(2-Hydroxy-ethyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-[2-(3-Chloro-4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-(2-hydroxy-ethyl)-urea;
1-[6-Fluoro-2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-(2-hydroxy-ethyl)-urea;
1-(2-Hydroxy-ethyl)-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-{2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-(2-hydroxy-ethyl)-urea;
1-{2-[4-(4-Acetyl-piperazin-1-yl)-3-chloro-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-(2-hydroxy-ethyl)-urea;
1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-3-(2-hydroxy-ethyl)-urea;
1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-5-methyl-pyrido[2,3-d]pyrimidin-7-yl}-3-(2-hydroxy-ethyl)-urea;
1-Ethyl-3-[2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-[2-(3-Chloro-4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-ethyl-urea;
1-Ethyl-3-[6-fluoro-2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Ethyl-3-[5-methyl-2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
l-{2-[4-(4-Acetyl-piperazin-l-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-ethyl-urea;
1-{2-[4-(4-Acetyl-piperazin-1-yl)-3-chloro-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-ethyl-urea;

1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-3-ethyl-urea;
1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-5-methyl-pyrido[2,3-d]pyrimidin-7-yl}-3-ethyl-urea;
1-tert-Butyl-3-(2-phenylamino-pyrido[2,3-d]pyrimidin-7-yl)-urea;

1-tert-Butyl-3-[2-(4-fluoro-3-methyl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(4-Chloro-phenyl)-3-[2-(4-fluoro-3-methyl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Isopropyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-tert-Butyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-Cyclohexyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-Cyclopentyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimdin-7-yl]-urea;
1-Cyclohexyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-l-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-Cyclopentyl-3-[5-methyl-2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimdin-7-yl]-urea;
1-Cyclohexyl-3-[6-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[6-bromo-2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-Cyclohexyl-3-[6-cyano-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[6-chloro-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[6-fluoro-5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[6-bromo-5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[6-chloro-5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Isopropyl-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Ethyl-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-[5-Methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Methyl-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-l-methyl-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(4-Hydroxy-cyclohexyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(4-Amino-cyclohexyl)-3-[2-(4-piperazin-l-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(2-Dimethylamino-ethyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-(3-Morpholino-4-yl-propyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
3-Cyclohexyl-l-methyl-l-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
N,N-Dimethyl-N'-[5-methyl-2-[[4-(1-piperazinyl)phenyl]-amino]-pyrido[2,3-d]pyrimidin-7-yl]-sulfamide;
1-Cyclohexyl-3-[5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-thiourea;
N-[2-(4-Piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-acetamide;

4-[7-(3-Cyclohexyl-ureido)-pyrido[2,3-d]pyrimidin-2-ylamino]-benzenesulfonamide;

1-Cyclohexyl-3-{2-[4-(1-piperazin-1-yl-methanoyl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-Cyclohexyl-3-[2-(4-fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(2-{4-[4-(2-Amino-4-methyl-pentanoyl)-piperazin-1-yl]-phenylamino}-pyrido[2,3-d]pyrimidin-7-yl)-3-cyclohexyl-urea;
and 1-(2-{4-[4-(2-Amino-3-methyl-butanoyl)-piperazin-1-yl]-phenylamino}-pyrido[2,3-d]pyrimidin-7-yl)-3-cyclohexyl-urea.

8. A compound selected from:
1-tert-Butyl-3-[2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-Cyclohexyl-3-[2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-Ethyl-3-[2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;

1-(Hydroxy-ethyl)-3-[2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-tert-Butyl-3-[6-fluoro-2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[6-fluoro-2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Ethyl-3-[6-fluoro-2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-[6-Fluoro-2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-(2-hydroxy-ethyl)-urea;

1-tert-Butyl-3-[5-methyl-2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-[5-methyl-2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Ethyl-3-[5-methyl-2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea; and 1-(2-Hydroxy-ethyl)-3-[5-methyl-2-(pyridin-4-ylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea.

9. A compound selected from:
4-{4-[7-(3-tert-Butyl-ureido)-pyrido[2,3-d]pyrimidin-2-ylamino]-phenyl}-piperazine-1-carboxylic acid tert-butyl ester;

4-{4-[7-(3-Cyclohexyl-ureido)-pyrido[2,3-d]pyrimidin-2-ylamino]-phenyl}-piperazine-1-carboxylic acid tert-butyl ester;

1-(3-Hydroxy-propyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-((S)-1-Hydroxymethyl-3-methyl-butyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
4-Methyl-piperazine-l-carboxylic acid [2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-amide;
Morpholine-4-carboxylic acid [2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-amide;
3-[2-(4-Piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-1,1-dipropyl urea;

Piperazine-l-carboxylic acid[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-amide;
1-((R)-1-Hydroxymethyl-2-methyl-propyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1,1-Bis-(2-hydroxy-ethyl)-3-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-[6-Bromo-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-tert-butyl-urea;
1-[6-Bromo-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-methyl-urea;
1-{6-Bromo-2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-tert-butyl-urea;
1-{6-Bromo-2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-cyclohexyl-urea;
1-[2-(4-Fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-(3-morpholin-4-yl-propyl)-urea;

1-[2-(4-Fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-(2-hydroxy-ethyl)-urea;

1-(2-Amino-ethyl)-3-[2-(4-fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-(2-Dimethylamino-ethyl)-3-[2-(4-fluoro-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
1-Cyclohexyl-3-{2-[4-(3,3-dimethyl-piperazin-1-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-tert-Butyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-fluoro-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-{2-[4-(4-Acetyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-3-(3-morpholin-4-yl-propyl)-urea;

1-tert-Butyl-3-{6-chloro-2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;
3-Cyclohexyl-1-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-1-methyl-urea;
3-Cyclohexyl-l-ethyl-1-[2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea;
3-tert-Butyl-1-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-1-ethyl-urea;
1-[5-Methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-propyl-urea;
7-(3-tert-Butyl-ureido)-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidine-6-carboxylic acid ethyl ester;
1-[6-Fluoro-5-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido[2,3-d]pyrimidin-7-yl]-3-isopropyl-urea;

1-Cyclohexyl-3-{2-[4-(3,3-dimethyl-piperazin-l-yl)-phenylamino]-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-Cyclohexyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-methyl-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-tert-Butyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-methyl-pyrido[2,3-d]pyrimidin-7-yl}-urea;
1-tert-Butyl-3-[6-methyl-2-(4-piperazin-1-yl-phenylamino)-pyrido [2,3-d] pyrimidin-7-yl] -urea;
1-{2-[4-(cis-3,5-Dimethyl-piperazin-1-yl)-phenylamino]-6-methyl-pyrido[2,3-d]pyrimidin-7-yl}-3-isopropyl-urea;
1-Cyclopropyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-methyl-pyrido[2,3-d]pyrimidin-7-yl}-urea; and 1-tert-Butyl-3-{2-[4-(cis-3,5-dimethyl-piperazin-1-yl)-phenylamino]-6-ethyl-pyrido[2,3-d]pyrimidin-7-yl}-urea.

10. A pharmaceutical composition comprising a compound as claimed in any one of claims 1 to 9 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, diluent, or excipient.

11. The pharmaceutical composition of claim 10, which is for controlling proliferative disorders through a cdk inhibitory effect, the disorders being selected from the group consisting of cancer, psoriasis, and vascular smooth muscle cell proliferation associated with a disorder selected from the group consisting of atherosclerosis, postsurgical vascular stenosis, and restenosis in mammals.

12. The pharmaceutical composition of claim 10, which is for treating through a cdk inhibitory effect a subject suffering from diseases caused by vascular smooth muscle cell proliferation.

13. The pharmaceutical composition of claim 10, which is for treating through a cdk inhibitory effect a subject suffering from cancer.

14. The pharmaceutical composition of claim 10, which is for treating through a cdk inhibitory effect a subject suffering from a cancer related from breast cancer, large cell carcinoma, pancreas, colon, melanoma, lung, and leukemia.

15. Use of a compound or salt as claimed in any one of claims 1 to 9 in the preparation of a medicament for inhibiting a cdk enzyme.

16. The use of Claim 15 wherein said cdk is cdk1.

17. The use of Claim 15 wherein said cdk is cdk2.

18. The use of Claim 15 wherein said cdk is cdk4.

19. Use of a compound or salt as claimed in any one of claims 1 to 9 in the preparation of a medicament for inhibiting a growth factor-mediated tyrosine kinase.

20. The use of Claim 19 wherein said growth factor-mediated tyrosine kinase is platelet derived growth factor (PDGF).

21. The use of Claim 19 wherein said growth factor-mediated tyrosine kinase is fibroblast growth factor (FGF).