JPS5951288A - Novel 9-camptothecin and its preparation - Google Patents

Abstract

NEW MATERIAL:The 9-nitrocamptothecin of formula. USE:Intermediate for the synthesis of various 9-substituted camptothecin derivatives useful as carcinostatic agents, etc. PROCESS:Camptothecin is dissolved in concentrated sulfuric acid, and concentrated nitric acid is added slowly to the solution under ice cooling. The amount of the nitric acid is several times equivalent based on camptothecin. The mixture is stirred and made to react at room temperature for 24-72hr, and the produced reaction liquid is poured into water and extracted with chloroform. The chloroform layer is dried with anhydrous magnesium sulfate, the solvent is evaporated to dryness in vacuum, and the residue is separated and purified by silica gel chromatography.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel camptothecin conductor and a method for producing the same. More specifically, the present invention provides a novel substance, 9-nitrocamptothecin, represented by the formula, characterized in that camptothecin is treated with a small excess of concentrated nitric acid in concentrated sulfuric acid at room temperature. The present invention provides a method for producing 9-nitrocamptothecin, a novel substance represented by the above formula.

Camptothecin is a deciduous descendant tree (Cυ cry) t・LI+'
:c*+acumj, nata Nyssaceae
), etc. It is an alkaloid extracted and isolated from plants such as (
・It is an antitumor substance with a unique mechanism of action, and has been shown to have strong anticancer effects against experimentally transplanted cancers such as mouse leukemia L 1240 and rat Walker 256 cancer. However, its usefulness as a medical product is naturally limited due to its toxic effects.

Therefore, attempts have been made to chemically convert camptothecin into other substances, that is, to convert it into camptotenone derivatives, thereby reducing toxicity while retaining anticancer activity.

However, cambutothenone itself is sparingly soluble in various organic solvents, and cambutothenone is derived from the petro ring in its chemical structure, resulting in resistance to electrophilic substitution reactions ((). So, there are divine obstacles to converting into derivatives, and it is difficult to plan it on paper.
The reality is that it is not easy to obtain standard derivatives.

The present inventors previously used cambutothian as a starting material (・
Attempts were made to synthesize intermediate derivatives of O through chemical modification.
1' of camptothecin), (1, 2, obtained by catalytic reduction)
By using 6.7-titrahydronononeptothecin, we succeeded in producing 10-nitro or 11-nitro-camptothecin, which cannot be obtained by conventional nitration of camptothecin. The nitro group of the compound can be converted to an amine group by a reduction reaction, and this amino group can be converted to a hydroxyl group, halogen, etc. by subjecting it to a diazotization reaction.
As a result, they succeeded in synthesizing a cambutotenone derivative in which a second substituent was introduced at the 10th or 11th position.

Regarding the nitrated form of camptothecin, the synthesis of 12-nitrocamptothecin using sulfuric acid has been reported by Pan Pe1-chuar+ et al. in China;
℃・There are no reported cases yet.

The only known 9-position derivative of Cambutothian is 9-methoxycamptothecin, which is isolated from nature. Because it is an ingredient,
This has not been sufficiently studied.

The present inventors conducted experimental research on the chemical modification of position 9 of Cambutothian from the interest of the activity of cocoon silk derivatives at position 9, and found that when camptothecin was carefully dioxidized with concentrated nitric acid with a small to medium excess of emetic acid, a constant M The nitration proceeds, and the resulting mononide is separated using chromatography using a gel filter.
It has been found that 9-nitrocamptothecin can be obtained together with nitrocamptothecin in good yields of 60-40%. The present invention was developed based on the above findings.

The present invention will be explained in detail below. First, 9 according to the present invention
- Describe the method for producing nitrocamptothecin.

The method for producing 9-nitrocamptothecin of the present invention involves treating cambutothian with a small excess of concentrated nitric acid in concentrated sulfuric acid. To explain preferred embodiments of this production method, first, camptothecin is dissolved in daughter sulfuric acid. F L
Then, while cooling with water, slowly add concentrated nitric acid in an amount several times equivalent to camptothecin. This is then stirred at room temperature. The reaction is completed in 24 to 72 hours, and the resulting reaction solution is poured into several times the amount of water and extracted several times with chloroform. After drying this chloroform layer with anhydrous magnesium sulfate, the solvent was dried under reduced pressure, and the residue was separated using 100% silica gel chromatography (chloroform). Together with 12-nitrocamptothecin, 9-nitrocanradotenone is obtained in a yield of 50-40%.

This 9-nitrocamptothecin is a key intermediate in the synthesis of the divine 9-16 compound/butothian derivative. Using this 9-nitrocanradotenone as a starting material, known or novel 9-substituted camptothecins can be synthesized, for example, as follows.

9-Nitrocamptothecin is converted into its nitro amine group by subjecting it to reduction or catalytic reaction with a metal such as iron or tin in a salt v, and it corresponds to the nitro group in a stable manner. It can be converted into a 9-amine form. The amine group of this 9-amine compound can be converted into various other functional groups by acylating the amine group or converting the amine group into a 9-arylamino compound or 9-alkylamino compound by converting it into a diazonium salt. can. 1 evening 11
The 9-amine compound is azotized in a miM aqueous solution, and then heated to convert it into a 9-hydroxy substituted compound, or to convert it into a 9-hydroxy substituted compound, or a 9-acyloxy compound or 9-alkoxy substituted with a human'roxy group. It can be transformed into a body. Furthermore, a 9-methoxy substituted product can be obtained by treating the above diazonium salt with methanol. Alternatively, the above 9-amine compound can be diisolated in hydrochloric acid or hydrobromic acid, and then treated with cuprous chloride or cuprous bromide to produce 9-chlorocambutothiane or 9-promothione. You can get what you want.

Examples of the present invention and various 9-substituted cambutylene 1
Reference examples of the production of tescin are given, but the present invention is not limited to these examples.U.0 Example 9 - Production of nitrocamptothecin
mot) in concentrated sulfuric acid (15 ml.) and cooled with water.
61% nitric acid (d:1, 38) (3.2 3ml
, 4 3. ID mmo7) was slowly added dropwise while stirring. After completion of the dropwise addition, the mixture was stirred at room temperature for 4 days.

The reaction solution was diluted with ice water (150M) and extracted with chloroform (1500fnlX3). After drying this chloroform layer with magnesium sulfate, it was dried under reduced pressure and the residue was purified using silica gel column chromatography (CHCL3).
12-nitrocamptothecin (2.23
0■, 65;, 7%) as well as the title compound (1.062
fflr, 616%) is obtained.

m. p. 190-192℃ (decomposition) (from AcOEt) MS: mle 393[M”:] (c2on45
N3o6=393) 1382, 1340, 1230,,
1150.105ONMR (in DMSO-cl 6) δ
:0.89(3H,t,J=7Hz,-CH'2Cdan3
), 1, 88 (2H, q, J=7Hz, -CH2CH
3), 5.34 (2H, s, C-5-H), 5, 43 (
2H,s,C17-H), 6.52(iH,s,C-2
0-OH), 7, 39(IH,S, C-14-H
), 8.02 (IH, m, C-11-H), 8.47-
8.59 (2H, m, C-10-H and C-'+2-1-1), 9.15 (IH.

s, C-7-J () Reference Example 1 Production of 9-aminocamptothecin/9-nitrocamptothecin (100 mjl, 0
．． 254nono7) to ethanol (30
ml! ), dissolved in a mixed solvent of dioxane (20 ml), added platinum oxide (20 my), and stirred for 1 hour.
Catalytic reduction is carried out at room temperature and pressure. After removing the catalyst and drying the solvent under reduced pressure, the title compound was obtained quantitatively.

MS: mle 363 [M+,] (C20H17
N304=363)IRνKBram-1: 3490
,3390,1745,1650,1605,1690
.

aX 1685, 1160, 81O NMR (in DMSO-d6) δppm; 0.91 (3H
, t. , J=7.5Hz), 1.86(2H,q,
J=7.5Hz), 5.23 (2H, s), 5.
38 (2B, a, J=7.5Hz), 6.
7 5~B. 2 2 (5H, m), 73ro (
IH, s), 8.81 (IH, s).

Reference Example 2 Production of 9-acetaminocamptothecin 9-Aminocamptothecin (10 mg, 0.028 mmol) was suspended in chloroform (20 ml), and added with bili';7 (0.5 ml). and acetic anhydride (0
．． 1d) and stirred at room temperature for 1 hour. After that, the solvent was dried under reduced pressure to obtain the title compound (9179.4%).
or can be obtained.

MS mle; 405 (M+) (C22H19N3
05=4[]5,) NMR (in Dlxso-d6) δ
ppm; 0.91 (3H, t, J=7.5Hz),
188 (2H,q, J=7.5Hz), 2.11 (3
H, s), 522 and 541 (two 2H'S+S
), 6.43 (IH, s), 7.22 (IH, s), 7
60-7, BO (3H, m), 8.85 (IH,
s), 10.52 (IH, s).

Reference Example 6 Production of 9-dimethylaminocamptothecin 9-aminecamptothecin (101 ng, 0.028 mma
The mixture was suspended in acetone (10ml), and anhydrous charcoal (30mg) and methyl iodide (1me) were added thereto and stirred at room temperature for 60 minutes. Thereafter, insoluble matter was removed by filtration for 14 hours, and the liquid was dried to give the title compound (8 mfl, 72.9%).

MS mle; 391 [Mto] (C22H
21N604-691,) Reference Example 4 Production of 9-hydroxycamptothecin 9-nitrocamptothecin (100m9.0.254
The resulting 9-aminocamptothecin was dissolved in 10% sulfuric acid, and while stirring in an ice-salt bath, sodium nitrite (19+ng, 0.280m
mot) water bath solution is slowly added, followed by stirring for 15 minutes, then the reaction is poured into hot water (100 mg) and boiled to reflux for 30 minutes. The reaction solution was diluted with ice water (100ml) and chloroform (IOM) was added and shaken. The precipitate 1' was collected and purified by silica gel column chromatography to obtain the title compound (32mg, Section 645). It will be done.

m, p, >6oo℃ (from Pyridine-CJOH) MS mle: 364 [M”] (C2oH1
6N205=364. ) NMR (in DMSO-d6) δ
ppm: 0.92 (3H, t, J=7.5Hz),
187 (2H,q, J=7.5Hz), 525 and 5.40 (two 2H's.

S), 7.1CI-7,75(3H,m), 1ro6(I
H,s), 8.84 (IH,s).

Reference example 5? -Preparation of acetoxycamptothecin 9-Hydroxycamptothecin (10+'lf, 0.0
27mm) to OO form (20m/)
Shu, to which pyridine (1-) and acetic anhydride (0,2d)
and stirred at room temperature for 2 hours. Thereafter, the title compound (9 mg, 821%) is obtained by drying under reduced pressure.

m, p, 205-207°C (CHC73-p-hexa
rie) MS mle; 406 (M+)' (
C22Hj 8N206"406.) NMR (DMSO
-d6) oppm: 0.90 (3H,i,,J=
7.5Hz), 1.90 (2H,q, J=7.5H
z), 2.12 (3H, s), 5.27 (2H, s),
569 (21-1, s), 6.41 (IH, s), 7.
40 (IH, s), 7. aO ~ 8.23 (3H, m),
8.71 (I H,s).

Reference Example 6 Production of 9-methoxycamptothecin 9-hydroxycamptothecin (2Qmg, 0.055
Mmo7) was dissolved in methanol to make it cloudy, 06% diazomethane ether solution (10ml) was added thereto, and the mixture was stirred at room temperature for 60 minutes.
Stir for an hour. Thereafter, the solvent was dried under pressure to obtain the title compound (21 mg, 100%).

m, p, 226-228℃ (decomposition) (CH2C72-
From CH30H) MS: mle 378 [M10:
] (C21H4BN205=378)JRνK”r
cm-': 3400.1750.1655.1610
．． 1590, 1365°ax 1265.1230, 1195, 1155, 1140,
1105゜1O NIJ ((in DMSO-d6) δ: 0.89(31(,
t, J=811z, -CH2Cdan3), 1.87(2H
, q, J=8Hz, -Cdan2CH3), 4.04 (3
1-1, s, C-9-och3), 5.25 (2H,
s, C-! :,(1),542(nH,s,C-17
-H), 6.49 (1H,s, C-20-OH), 7.
10-7.19(11], m, C-11-H), 7.3
2(1H,s,C-14-1-]), 7.73-7.7
6 (2H, m, C-10-H and psc-12-H),
883 (I H+ b + t-co 7-H) Reference example
7 Preparation of 9-ethquincamptothecin 9-hydroquincamptothecin (50 mg, 0167m
mot) was dissolved in DMF (10 ml), and anhydrous potassium carbonate (5D my) and ethyl bromide (2-) were dissolved in DMF (10 ml).
and stirred at room temperature for 5 hours. Thereafter, impurities were removed by filtering, the t'' solution was dried under pressure, and the residue was purified by silica gel column chromatography to obtain the title compound (35++g, 65.2%).

m, p, 218-221℃ (from cH2ct2) MS
mle: 392 (M”) (C22H2ON205=
392) NMR (in DMSO-d6) δppm:
0.89 (3H, t, J=7.5Hz), 1.68
(3H, t, 7.5Hz), 1.87 (2H, q
,, J=7.5Hz), 6.88 (2H, cl.

J = 7.5Hz), 5.27 and 5.40 (two
2H's, s), 6,45 (1H, s), 7.33 (I
H, s), 7.09-7.78 (3H, m), 8.
82 (IH.

S).

Reference Example 8 Production of 9-n-butoxycamptothecin 9-Hydroquine camptothecin (50 mf, 0.137 mmot) was dissolved in DMF (10 yd), and anhydrous charcoal 1 potassium (5 D my ) and n-butyl bromide (2++114 )
and stirred at room temperature for 5 hours. Thereafter, insoluble materials were removed by filtration, and the solution F was dried to dryness under reduced pressure. The residue was purified by silica gel column chromatography to obtain the title compound (42 mg, 730%).

m, p, 236-238℃ (cH2cz2-cn3oH
) ms mle: 420 [M”] (C24H2
4N205=420) NMR (in DMSO-d6) Op
pm: 0.91 (3H, t, J=7.5Hz),
102 (3H, t, 7.5Hz), 1.10-1.18
(4B, m), 1.90 (2H, q.

J = 7.5Hz), filter 70 (2H, t, J = 7.5Hz
), 526 and 569 (two 2H's, s),
6.42 (II-I, s), 7.31 (1H, s)
, 700-7.80 (5I-1, m), 8.75 (IH
,s).

Reference Example 9 Production of 9-chlorocamptothecin 9-nitrocamptothecin (100rng, O254m
9-aminocamptothecin obtained by catalytic reduction of 9-aminocamptothecin obtained by catalytic reduction of 14% salt m (8rne) was added to Oki Sodium Nitrate (19m7.0.2) while stirring in an ice-salt bath.
Gradually add an aqueous solution of 80 mmot).

After the completion of the dropwise addition and stirring for 15 minutes, the diasonium water-resistant bath solution was mixed with cuprous chloride (12
5'llll? , 1.270 mmot) into an 18% hydrochloric acid aqueous solution (10 Biao). After completion of the dropwise addition, stirring was continued for 1 hour. The reaction solution was poured into ice water (2D Drnl
V) and extracted with chloroform (isoml, x5
)do. After drying the 0O form layer with magnesium sulfate and distilling it off under reduced pressure, the title compound (filter Z5■, 3
85% yield) is obtained.

m, p, 257-260°C (decomposed) (from AcOEt) MS: m/e 382[M+l, 384C'M
+2) (C2oH+ 5N20+c7=382)I
Rv¥:yM Cm-':3430.1735. '1
655.1605.1585.1230°1150.1
045 NMR (in DM1045N) δ: 0.88 (3H,
t, J=7Hz, -CH2CH3), 1.87(2H,
q, J=7)1z, CH2CH5), 5.32 (2
H, s, C-5-H), 5.46 (2H, s, C-
17-H), 6.51 (IH, s, C-20-OH),
7.37 (IH, s, C-14-H), 7.83-7.
89 (2H, m, C-10-H and C-12-H),
8.12-8.24 (IH, m, C-11-)]), 8
．． 93 (IH, s, C-7-H) Reference Example 10 Production of 9-promocamptodene 9-Nitrocambutote7no (100++If, o254
9-aminocamptothecin obtained by catalytic reduction of 9-aminocamptothecin (9-aminocamptothecin) obtained by catalytic reduction of 9-aminocamptothecin (9-aminocamptothecin) was dissolved in 15% aqueous hydrogen bromide (8 tnIV), and while stirring in an ice-salt bath, sodium nitrite (19 m 9.
0.280 mmot) is gradually added.

After the completion of the dropwise addition, after stirring for 15 minutes (TJ 9L), the aqueous azonium salt solution was heated to 60 to 70°C and heated to cuprous bromide (1821 ng, 1.2'70 mmot) (
Gradually drop it into an aqueous solution of hydrogen bromide (10 + + + l) and continue stirring for 1 hour after the completion of IK. The reaction solution is diluted with ice water (200 Td!) and extracted with chloroporm. (150++11×3) This chloroform layer is dried over magnesium sulfate and then evaporated under reduced pressure to obtain the title compound (63 mg, 58.0% yield).

T11. p, 260-262℃ (minute angle t) (AcO
From Et) MS: m/e 426 [M+ko,
428 [Ms 2'J (C2 (1815N20
4Br=426) IRvWFM Cn1-” :343
0, 1735, 1655, 1605, 1585
, 1235°1160.1045 NMR1045N d6) δ: 0.89 (3H
, L, J=7Hz, -C) (2CH3), 1.87 (2
H, q, J=7Hz, -C12CH3), 5.33
(2H,s,C-5-H), 5.43(2H,s,C
-17-H), 6.52 (IH,s, C-20-OH)
, 737 (IH,s, C-14-H), 7.78 (IH
, L, J=81-1z, C-11-)]), 8.0
3 to 8.87 (2H, m, C-10-11OJ: and C-
12-H), 8.88 (IH, s, C-7-H)

Claims (2)

[Claims] (1) Formula A novel 9-nitrocamp)77n0 (2) A method for producing 9-nitrocamptothecin, which comprises treating cambutotenone in concentrated sulfuric acid with a small excess of concentrated nitric acid.