WO2008119718A1

WO2008119718A1 - Compounds which have activity at m1 receptor and their uses in medicine

Info

Publication number: WO2008119718A1
Application number: PCT/EP2008/053597
Authority: WO
Inventors: David Gwyn Cooper; Ian Thomson Forbes; Vincenzo Garzya; Jian Jin; Graham Walker; Paul Adrian Wyman; Zheng Yang
Original assignee: Glaxo Group Limited
Priority date: 2007-03-29
Filing date: 2008-03-27
Publication date: 2008-10-09
Also published as: GB0706165D0

Abstract

Compounds of formula (I) or a salt thereof are provided: (I) wherein R4, R5, R6, Q and R are as defined in the description. Uses of the compounds as medicaments and in the manufacture of medicaments for treating psychotic disorders and cognitive impairments are disclosed. The invention further discloses pharmaceutical compositions comprising the compounds.

Description

Compounds which have activity at M₁ receptor and their uses in medicine

This invention relates to novel compounds, pharmaceutical compositions containing them and their use in therapy, in particular as antipsychotic agents.

Muscarinic acetylcholine receptors are members of the G protein coupled receptor superfamily which mediate the actions of the neurotransmitter acetylcholine in both the central and peripheral nervous system. Five muscarinic receptor subtypes have been cloned, M₁ to M₅. The muscarinic M₁ receptor is predominantly expressed in the cerebral cortex and hippocampus, although it is also expressed in the periphery e.g. exocrine glands.

Muscarinic receptors in the central nervous system, especially M₁, play a critical role in mediating higher cognitive processing. Diseases associated with cognitive impairments, such as Alzheimer's disease, are accompanied by loss of cholinergic neurons in the basal forebrain. Furthermore, in animal models, blockade or lesion of central cholinergic pathways results in profound cognitive deficits.

Cholinergic replacement therapy has largely been based on the use of acetylcholinesterase inhibitors to prevent the breakdown of endogenous acetylcholine. These compounds have shown efficacy versus symptomatic cognitive decline in the clinic, but give rise to side effects resulting from stimulation of peripheral muscarinic receptors including disturbed gastrointestinal motility and nausea.

The dopamine hypothesis of schizophrenia suggests that excess dopaminergic stimulation is responsible for the positive symptoms of the disease, hence the utility of dopamine receptor antagonists to reduce psychotic symptoms. However, conventional dopamine receptor antagonists can cause extrapyramidal side effects (EPS) in patients, including tremor and tardive dyskinesias.

M₁ receptor agonists have been sought for the symptomatic treatment of cognitive decline. More recently, a number of groups have shown that muscarinic receptor agonists display an atypical antipsychotic-like profile in a range of pre-clinical paradigms. The muscarinic agonist, xanomeline, reverses a number of dopamine driven behaviours, including amphetamine induced locomotion in rats, apomorphine induced climbing in mice, dopamine agonist driven turning in unilateral 6-OH-DA lesioned rats and amphetamine- induced motor unrest in monkeys (without EPS liability). It also has been shown to inhibit A10, but not A9, dopamine cell firing and conditioned avoidance and induces c-fos expression in prefrontal cortex and nucleus accumbens, but not in striatum in rats. These data are all suggestive of an atypical antipsychotic-like profile. Xanomeline has also been shown to reduce psychotic symptoms such as suspiciousness, hallucinations and delusions in Alzheimer's patients. However, the relatively non-selective nature of the compound gives rise to dose-limiting peripheral cholinergic side effects.

Certain M₁ receptor agonists are known, for example in WO2007/036718, WO2007/036715, WO2007/03671 1 , WO2007/107566, WO2007/107567 and WO2007/107565. We have now found a novel group of compounds which are M₁ receptor agonists.

In a first aspect therefore, the invention provides a compound of formula (I) or a salt thereof:

(I) wherein:

• R is C-i-βalkyl attached at the 2, 3 or 4-position of the piperidine ring;

• R⁴ is hydrogen or fluoro;

• R⁵ is selected from hydrogen, halogen, cyano, C_1-6alkyl (optionally substituted with one or more fluorine atoms) and C₁^aIkOXy (optionally substituted with one or more fluorine atoms);

• R⁶ is selected from hydrogen, halogen, cyano, C_1-6alkyl (optionally substituted with one or more fluorine atoms), C_1-6alkylsulfonyl, C_3-6cycloalkyl (optionally substituted with one or more fluorine atoms) and C_1-6alkoxy (optionally substituted with one or more fluorine atoms); and

• Q is hydrogen or C_1-6alkyl.

As used herein, the term "alkyl" refers to straight or branched hydrocarbon chains containing the specified number of carbon atoms. For example, C-i-βalkyl means a straight or branched alkyl containing at least 1 , and at most 6, carbon atoms. C_1-4alkyl means a straight or branched alkyl containing at least 1 , and at most 4, carbon atoms. C_1-3alkyl means a straight or branched alkyl containing at least 1 , and at most 3, carbon atoms. Examples of "C_1-6alkyl" include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n- pentyl, n-hexyl, isobutyl, isopropyl, t-butyl and 1 ,1-dimethylpropyl. As used herein, the term "alkoxy" refers to a straight or branched alkoxy group containing the specified number of carbon atoms. For example, C_1-6alkoxy means a straight or branched alkoxy group containing at least 1 , and at most 6, carbon atoms. Examples of "Ci_-6alkoxy" as used herein include, but are not limited to, methoxy, ethoxy, propoxy, prop- 2-oxy, butoxy, but-2-oxy, 1-methylethyl-oxy, 2-methylprop-1-oxy, 2-methylprop-2-oxy, pentoxy or hexyloxy.

As used herein, the term "cycloalkyl" refers to a non-aromatic hydrocarbon ring containing the specified number of carbon atoms. For example, C_3-6cycloalkyl means a non-aromatic carbocyclic ring containing at least 3, and at most 6, ring carbon atoms. Examples of "C_3- ₆cycloalkyl" as used herein include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

As used herein, the term "C_1-6alkylsulfonyl" refers to a group SO₂-C_1-6alkyl, wherein C_1- ₆alkyl is as defined above.

As used herein, the term "C_3-6cycloalkylC_1-6alkyr as used herein refers to a group C_3- ₆cycloalkyl-Ci_-6alkyl wherein C_3-6cycloalkyl and Ci_-6alkyl are as defined above.

As used herein, the term "substituted" refers to substitution with the named substituent or substituents, multiple degrees of substitution being allowed unless otherwise stated. For example, there may be 1 , 2 or 3 substituents on a given substituted group. For example, if R⁵ is a C_1-6alkyl group, it may be substituted by 1 , 2, 3 or 4 fluoro groups; and if R⁵ is a Ci_-6alkoxy group, it may be substituted by 1 , 2, 3 or 4 fluoro groups.

As used herein, the term "halogen" (or the abbreviated form "halo") refers to the elements fluorine (which may be abbreviated to "fluoro" or "F"), chlorine (which may be abbreviated to "chloro" or "Cl"), bromine (which may be abbreviated to "bromo" or "Br") and iodine (which may be abbreviated to "iodo" or "I"). Examples of halogens are fluorine, chlorine and bromine.

In one embodiment, R is C_1-3alkyl attached at the 2, 3 or 4-position of the piperidine ring. In a further embodiment, R is methyl or ethyl attached at the 2, 3 or 4-position of the piperidine ring. In a further embodiment, R is methyl attached at the 2, 3 or 4 position of the piperidine ring.

In one embodiment, R⁴ is hydrogen.

In one embodiment, R⁵ is selected from hydrogen, halogen, cyano, Ci_-6alkyl (optionally substituted with one, two or three fluorine atoms) and

(optionally substituted with one, two or three fluorine atoms). In one embodiment, R⁵ is selected from hydrogen, chloro, bromo, fluoro, Ci_-4 alkyl (optionally substituted with one or more fluorine atoms) and C_1-4alkoxy.

In one embodiment, R⁵ is selected from hydrogen, chloro, bromo, fluoro, Ci_-4 alkyl (optionally substituted with one, two or three fluorine atoms) and C_1-4alkoxy.

In one embodiment, R⁵ is selected from hydrogen, chloro, bromo, fluoro, methyl, ethyl, methoxy and trifluoromethyl.

In one embodiment, R⁵ is hydrogen or fluoro. In one embodiment, R⁵ is hydrogen.

In one embodiment, R⁶ is selected from hydrogen, halogen, cyano, Ci_-6alkyl (optionally substituted with one or more fluorine atoms (for example one, two or three fluorine atoms)), C_3-6cycloalkyl (optionally substituted with one or more fluorine atoms (for example one, two or three fluorine atoms)) and Ci_-6alkoxy (optionally substituted with one or more fluorine atoms (for example one, two or three fluorine atoms)).

In one embodiment, R⁶ is Ci_-6alkyl.

In one embodiment of the invention, R⁶ is selected from chloro, bromo, fluoro, methyl, ethyl, isopropyl, cyclopropyl, methoxy, trifluoromethoxy and trifluoromethyl, for example chloro, fluoro, methyl, cyclopropyl, methoxy, trifluoromethoxy and trifluoromethyl.

In one embodiment, R⁶ is selected from chloro, fluoro, methyl, cyclopropyl, methoxy, trifluoromethoxy and trifluoromethyl.

In one embodiment, R⁶ is selected from methyl, fluoro, chloro, methoxy and cyclopropyl.

In one embodiment of the invention, R⁶ is selected from chloro, methyl and methoxy.

In one embodiment, R⁶ is methyl.

In one embodiment of the invention, Q is selected from hydrogen and Ci_-3alkyl. In one embodiment, Q is hydrogen or methyl. In one embodiment, Q is hydrogen.

In one embodiment, the invention provides a compound of formula (I') or a salt or solvate thereof:

(I^') wherein:

• R is C-i-βalkyl attached at the 2, 3 or 4-position of the piperidine ring;

• R⁴ is hydrogen or fluoro;

• R⁵ is selected from hydrogen, halogen, cyano, C_1-6alkyl, C_1-6alkyl substituted with one or more fluorine atoms, Ci_-6 alkoxy, and Ci_-6 alkoxy substituted with one or more fluorine atoms;

• R⁶ is selected from hydrogen, halogen, cyano, C_1-6alkyl, C_1-6alkyl substituted with one or more fluorine atoms, d_-6alkylsulfonyl, C_3-6cycloalkyl, C_3-6cycloalkyl substituted with one or more fluorine atoms, Ci_-6 alkoxy and Ci_-6 alkoxy substituted with one or more fluorine atoms; and

• Q is hydrogen or Ci_-6alkyl.

In another embodiment of the invention, there is provided a compound of formula (Ia) or a salt or solvate thereof:

(Ia) wherein:

• R is Ci_-6 alkyl attached at the 2, 3 or 4-position of the piperidine ring;

• R⁴ is hydrogen or fluoro;

• R⁵ is selected from hydrogen, halogen, C_1-6alkyl, C_1-6alkyl substituted with one or more fluorine atoms, Ci_-6 alkoxy, and Ci_-6 alkoxy substituted with one or more fluorine atoms; and

• R⁶ is selected from hydrogen, halogen, C_1-6alkyl, Ci_-6 alkyl substituted with one or more fluorine atoms, C_3-6cycloalkyl, C_3-6cycloalkyl substituted with one or more fluorine atoms, Ci_-6 alkoxy and Ci_-6 alkoxy substituted with one or more fluorine atoms. In another embodiment, the invention provides a compound of formula (Ib) or a salt or solvate thereof:

(Ib) wherein:

• R is C_1-6 alkyl attached at the 2, 3 or 4-position of the piperidine ring; and

• R⁶ is selected from hydrogen, halogen, C_1-6alkyl, C_1-6 alkyl substituted with one or more fluorine atoms, C_3-6cycloalkyl, C_3-6cycloalkyl substituted with one or more fluorine atoms, C_1-6 alkoxy and C_1-6 alkoxy substituted with one or more fluorine atoms.

All features and embodiments for formula (I) apply to compounds of formula (I'), (Ia) and (Ib) mutatis mutandis. Hereinafter, all references to compounds of formula (I) include compounds of formula (I'), (Ia) and (Ib).

In one embodiment the salt of the compound of formula (I) is a pharmaceutically acceptable salt. In one embodiment, the invention provides a compound of formula (I), or a pharmaceutically acceptable salt thereof.

It will be appreciated that for use in medicine the salts of formula (I) should be pharmaceutically acceptable. Suitable salts will be apparent to those skilled in the art and include for example mono- or di- basic salts formed with inorganic acids e.g. hydrochloric, hydrobromic, sulfuric, nitric, sulfamic phosphoric, hydroiodic, phosphoric or metaphosphoric acid; and with organic acids, such as tartaric, acetic, trifluoroacetic, citric, malic, lactic, fumaric, benzoic, formic, propionic, glycolic, gluconic, maleic, succinic, (1 R)- (-)-IO-camphorsulphonic, (1 S)-(+)-10-camphorsulphonic, isothionic, mucic, gentisic, isonicotinic, saccharic, glucuronic, furoic, glutamic, ascorbic, anthranilic, salicylic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic, ethanesulfonic, pantothenic, stearic, sulfinilic, alginic, galacturonic and arylsulfonic, for example naphthalene-1 ,5- disulphonic, naphthalene-1 ,3-disulphonic, benzenesulfonic, and p-toluenesulfonic, acids. Other non-pharmaceutically acceptable salts e.g. oxalates, may be used, for example in the isolation of compounds of formula (I) and are included within the scope of this invention. The compounds of the present invention may be in the form of their free base or pharmaceutically acceptable salts thereof, particularly the monohydrochloride, monoformate or monotrifluoroacetate salts. Certain of the compounds of formula (I) may form acid addition salts with less than one (for example, 0.5 equivalent of a dibasic acid) or one or more equivalents of an acid. The present invention includes within its scope all possible stoichiometric and non-stoichiometric forms thereof.

Solvates of the compounds of formula (I) and solvates of the salts of compounds of formula (I) are included within the scope of the present invention. As used herein, the term "solvate" refers to a complex of variable stoichiometry formed by a solute (in this invention, a compound of formula (I) or a salt thereof) and a solvent. Those skilled in the art of organic chemistry will appreciate that many organic componds can form such complexes with solvents in which they are reacted or from which they are precipitated or crystallised. Such solvents for the purpose of the invention may not interfere with the biological activity of the solute. Examples of suitable solvents include, but are not limited to, water, methanol, ethanol and acetic acid. Preferably the solvent used is a pharmaceutically acceptable solvant. Examples of suitable pharmaceutically acceptable solvents include, without limitation, water, ethanol and acetic acid. Most preferably the solvent used is water. Where the solvent used is water such a solvate may then also be referred to as a hydrate.

The compounds of formula (I) may have the ability to crystallise in more than one form. This is a characteristic known as polymorphism, and it is understood that such polymorphic forms ("polymorphs") are within the scope of formula (I). Polymorphism generally can occur as a response to changes in temperature or pressure or both and can also result from variations in the crystallisation process. Polymorphs can be distinguished by various physical characteristics known in the art such as x-ray diffraction patterns, solubility, and melting point.

It will be appreciated by those skilled in the art that certain protected derivatives of compounds of formula (I), which may be made prior to a final deprotection stage, may not possess pharmacological activity as such, but may, in certain instances, be administered orally or parenterally and thereafter metabolised in the body to form compounds of the invention which are pharmacologically active. Such derivatives may therefore be described as "prodrugs". Further, certain compounds of the invention may act as prodrugs of other compounds of the invention. All protected derivatives and prodrugs of compounds of the invention are included within the scope of the invention. Examples of suitable protecting groups for the compounds of the present invention are described in Drugs of Today, Volume 19, Number 9, 1983, pp 499 - 538 and in Topics in Chemistry, Chapter 31 , pp 306 - 316 and in "Design of Prodrugs" by H. Bundgaard, Elsevier, 1985, Chapter 1 (the disclosures in which documents are incorporated herein by reference). It will further be appreciated by those skilled in the art, that certain moieties, known to those skilled in the art as "pro-moieties", for example as described by H. Bundgaard in "Design of Prodrugs" (the disclosure in which document is incorporated herein by reference) may be placed on appropriate functionalities when such functionalities are present within compounds of the invention. Possible prodrugs for some compounds of the invention include : esters, carbonate esters, hemi-esters, phosphate esters, nitro esters, sulfate esters, sulfoxides, amides, carbamates, azo-compounds, phosphamides, glycosides, ethers, acetals and ketals.

Hereinafter, compounds of formula (I) (whether in solvated or unsolvated form) or their pharmaceutically acceptable salts (whether in solvated or unsolvated form) or prodrugs thereof defined in any aspect of the invention (except intermediate compounds in chemical processes) are referred to as "compounds of the invention".

The invention also includes all suitable isotopic variations of a compound of the invention. An isotopic variation of a compound of the invention is defined as one in which at least one atom is replaced by an atom having the same atomic number but an atomic mass different from the atomic mass usually found in nature. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulphur, fluorine and chlorine such as ²H, ³H, ¹³C, ¹⁴C, ¹⁵N, ¹⁷O, ¹⁸O, ³¹P, ³²P, ³⁵S, ¹⁸F and ³⁶CI, respectively. Certain isotopic variations of the invention, for example, those in which a radioactive isotope such as ³H or ¹⁴C is incorporated, are useful in drug and/or substrate tissue distribution studies. Tritiated, i.e., ³H, and carbon-14, i.e., ¹⁴C, isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with isotopes such as deuterium, i.e., ²H, may afford certain therapeutic advantages resulting from greater metabolic stability, for example, increased in vivo half-life or reduced dosage requirements and hence may be preferred in some circumstances. Isotopic variations of the compounds of the invention can generally be prepared by conventional procedures such as by the illustrative methods or by the preparations described in the Examples hereafter using appropriate isotopic variations of suitable reagents.

It will be appreciated that compounds of formula (I) can exist in cis or trans isomeric forms (the R group when at the 2- or 3-position on the piperidine ring in relation to the benzimidazolone ring).

It will be appreciated that the cis form may be drawn in the following different ways, although both represent the same isomeric form:

It will be appreciated that the trans form may be drawn in the following different ways, although both represent the same isomeric form:

The individual isomers {cis and trans) and mixtures of these are included within the scope of the present invention. The isomers may be separated one from the other by the usual methods or by methods detailed for the example compounds below. Any given isomer may also be obtained by stereospecific or asymmetric synthesis. The invention also extends to any tautomeric forms and mixtures thereof.

In one embodiment, the compounds of formula (I) are trans isomers.

In another embodiment, the compounds of formula (I) are cis isomers.

Mixtures of cis- and trans- compounds, or compounds in which the cis/trans conformation have not been determined, are drawn herein as shown below:

Particular compounds according to the invention include those specifically exemplified in the Examples section and named hereinafter including, without limitation:-

6-methyl-1-[4-methyl-1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3-dihydro-2H- benzimidazol-2-one;

6-methyl-1-[3-methyl-1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3-dihydro-2H- benzimidazol-2-one;

6-methyl-1-[2-methyl-1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3-dihydro-2H- benzimidazol-2-one; and salts thereof. In one embodiment, the salt of a compound listed above is a pharmaceutically acceptable salt.

In one embodiment, the salt is the the hydrochloride salt.

In one embodiment the salt is the trifluoroacetate salt.

In one embodiment, the salt is the formate salt.

A specific example of a salt of the present invention is:

6-methyl-1-[4-methyl-1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3-dihydro-2H- benzimidazol-2-one hydrochloride.

Further specific examples of salts of the present invention are:

6-methyl-1-[3-methyl-1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3-dihydro-2H- benzimidazol-2-one hydrochloride; and

6-methyl-1-[2-methyl-1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3-dihydro-2H- benzimidazol-2-one hydrochloride.

Compounds of the invention may be prepared by methods known in the art of organic synthesis as set forth in part by the following synthesis schemes. In the following reaction schemes and hereafter, unless otherwise stated, all the groups are as defined in the first aspect. It is also recognised that in all of the schemes described below, it is well understood that protecting groups for sensitive or reactive groups are employed where necessary in accordance with general principles of chemistry. Protecting groups are manipulated according to standard methods of organic synthesis (T. W. Greene and P. G. M. Wuts (1991 ) Protecting Groups in Organic Synthesis, John Wiley & Sons). These groups are removed at a convenient stage of the compound synthesis using methods that are readily apparent to those skilled in the art. The selection of processes as well as the reaction conditions and order of their execution shall be consistent with the preparation of compounds of the invention.

In a further aspect, the invention provides a general process (A1 ) for preparing compounds of formula (I), in which Q is H, which process comprises:

coupling a compound of formula (II)

with a compound of formula (III)

wherein

R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, and R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶.

The reaction is carried out under conditions suitable for reductive alkylation. The reductive alkylation reaction is typically carried out using sodium triacetoxyborohydride in dichloroethane, optionally in the presence of triethylamine, and optionally in the presence of titanium tetraisopropoxide. Alternatively sodium cyanoborohydride can be used as the reducing reagent in solvents such as methanol or ethanol, or the reductive alkylation can be effected under catalytic hydrogenation conditions using a palladium catalyst. In a further variation, the compounds (II) and (III) can be condensed under dehydrating conditions e.g. molecular sieves or magnesium sulfate, and the resultant imine or enamine reduced using for example sodium borohydride or by catalytic hydrogenation.

A modification of general process (A1 ) is required where Q is C_1-6alkyl. Thus, in general process (A2), a compound of formula (II) can be reacted with a compound of formula (III) in the presence of a source of cyanide, e.g. potassium cyanide or acetone cyanohydrin, to form the cyano intermediate (XXXX) which can be reacted with an alkyl Grignard reagent QMgX to form compounds of formula (I).

wherein:

R is a group R as previously defined, or a group convertible to R, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, Q is Ci_-6alkyl, and X is chloro, bromo or iodo.

The reaction is carried out using conditions similar to those described in the literature (Arch Pharm (Weinheim), 1987, 320 (4), 348-361 ). The piperidine and ketone components are treated with potassium cyanide in water at pH3 or reacted with acetone cyanohydrin in dimethylacetamide at elevated temperature to form the adduct (XXXX).

Reaction of the adduct (XXXX) with the alkyl Grignard reagent QMgX in ether or tetrahydrofuran provides compounds of formula (I).

In one aspect, the invention provides a compound of formula (XXXX) or salts thereof wherein R⁴ , R⁵ , R⁶ and R' are as hereinbefore defined.

In a further aspect, the invention provides a general process (B) for preparing compounds of formula (I) which process comprises:

coupling a compound of formula (IV)

with a compound of formula (V) o

(V)

wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, Q is hydrogen or d-βalkyl, and X and Y both represent leaving groups. X and Y can be the same or different and examples are Cl, PhO, EtO, imidazole. When X and Y are both Cl, i.e. phosgene, this reagent can be generated in situ e.g. from diphosgene or triphosgene.

In one aspect, the invention provides a compound of formula (IV) or salts thereof wherein R⁴ , R⁵ , R⁶ , R' and Q are as hereinbefore defined.

The above reaction is carried out using standard methodology e.g. reacting the diamine (IV) with the reagent (V) in an inert solvent for example dichloromethane or toluene or dimethylformamide, optionally in the presence of a base such as triethylamine or potassium carbonate, and optionally with heating.

In a further aspect, the invention provides a general process (C) for preparing compounds of formula (I) which process comprises:

treatment of a compound of formula (Vl)

with a palladium or copper catalyst (VII) to effect an intramolecular cyclisation

wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, Q is hydrogen or Ci_-6alkyl, and Z is a leaving group such as bromo, iodo, chloro or triflate.

In one aspect, the invention provides a compound of formula (Vl) or salts thereof wherein R⁴ , R⁵ , R⁶ , R' and Z are as hereinbefore defined.

The cyclisation reaction can be carried out using a variety of palladium or copper reagents as described in the literature (JACS, 2003, 125, 6653, Tet. Lett., 2004, 45, 8535, or JACS, 2002, 124, 7421 ).

In a further aspect, the invention provides a general process (D) for preparing compounds of formula (I) which process comprises:

reaction of a compound of formula (X)

wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, and Q is hydrogen or Ci_-6alkyl;

with diphenylphosphoryl azide or other reagent/combination of reagents to effect the Curtius rearrangement of compound (X), followed by intramolecular cyclisation.

In one aspect, the invention provides a compound of formula (X) or salts thereof wherein R⁴ , R⁵ , R⁶ , R' and Q are as hereinbefore defined.

The Curtius rearrangement is typically carried out by mixing the two reactants in an inert solvent such as toluene, optionally with heating.

In a further aspect, the invention provides a general process (E) for preparing compounds of formula (I) which process comprises:

coupling a compound of formul

with a compound of formula (XII)

wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, Q is hydrogen or d-βalkyl, and Z is hydroxy or a leaving group such as chloro, bromo or iodo, or alkyl/aryl sulfonate.

The alkylation reaction (Z = a leaving group) can be carried out under classical alkylation or Mitsunobu reaction (Z = OH) conditions. Using classical alkylation conditions, the benzimidazolone intermediate (Xl) can be deprotonated using a base such as sodium hydride in an inert solvent such as dimethylformamide, and then treated with the alkylating reagent (XII), optionally with heating. The Mitsunobu reaction with (XII) Z = OH can be carried out using standard conditions e.g. triphenylphosphine and diethylazodicarboxylate in an inert solvent such as dichloromethane or tetrahydrofuran at room temperature.

In a further aspect, the invention provides a general process (F) for preparing compounds of formula (I) which process comprises:

coupling a compound of formula (II)

with a compound of formula (IX)

wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, Q is hydrogen, and Z is hydroxy or a leaving group such as chloro, bromo or iodo, or alkyl/aryl sulfonate.

The alkylation reaction (Z = a leaving group) can be carried out under classical alkylation or Mitsunobu reaction (Z = OH) conditions. Using classical alkylation conditions, the benzimidazolone intermediate (II) can be deprotonated using a base such as sodium hydride in an inert solvent such as dimethylformamide, and then treated with the alkylating reagent (IX), optionally with heating. The Mitsunobu reaction with (IX) Z = OH can be carried out using standard conditions e.g. triphenylphosphine and diethylazodicarboxylate in an inert solvent such as dichloromethane or tetrahydrofuran at room temperature. Conversion of R⁶ to R⁶ or interconversions of R⁶ may be accomplished as indicated below.

For example, when R⁶ is a halogen, it can be converted to an alkoxy, trifluoromethyl or methylsulphonyl group by copper catalysed reaction, using an alcohol, methyl fluorosulfonyl(difluoro)acetate or sodium methanesulphinate, respectively. It may also be converted to an alkyl group with an organometallic reagent, for example an alkylstannane.

As another example, when R⁶ is hydroxy, it may be converted to an alkoxy group by reaction with an alkyl halide or sulfonate, or to a trifluoromethoxy group by conversion to the xanthate followed by oxidation in the presence of fluoride ion.

As a further example, when R⁶ is methyl, it may be converted to trifluoromethyl by chlorination or bromination followed by displacement of the introduced halogens with fluoride.

Conversion of R⁵ to R⁵ or interconversions or R⁵ may be accomplished in a manner similar to that indicated for conversion of R⁶ to R⁶ or interconversions of R⁶.

Conversion of R⁴ to R⁴ may be accomplished in various ways; for example by displacement of a halide group by fluoride, or by fluorination of an organometallic derivative with a source of electrophilic fluorine such as N-fluorobenzenesulfonimide, or by decomposition of a diazonium tetrafluoroborate.

Compounds of formula (II) are generally known in the literature or can be prepared by a range of different processes for example:

(a) displacement of an ortho-fluoro or ortho-chloro nitrobenzene intermediate (XIII) with the amine (XIV), wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, and P represents a nitrogen protecting group (e.g. Boc, acetyl, trifluoroacetyl, ethoxycarbonyl, benzyloxycarbonyl), to give (XXIII), followed by reduction of the nitro group, cyclisation using phosgene or a phosgene equivalent, and deprotection of the piperidine nitrogen using standard literature conditions (Scheme 1 ).

Scheme 1.

Compounds of formula (XIII) are commercially available or can be prepared by standard methodology. The compound (XIV) in which P = Boc can be prepared by standard methodology.

(b) metal catalysed cyclisation of an intermediate (XV) followed by deprotection of the piperidine nitrogen, wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, P represents a nitrogen protecting group (e.g. Boc, acetyl, trifluoroacetyl, benzyloxycarbonyl), and Z represents a leaving group such as bromo, iodo, chloro or triflate. Reaction conditions for the Buchwald cyclisation are summarised in Process C. The urea (XV) can be prepared using any of the classical methods for urea formation as illustrated in Scheme 2. The starting materials for this process are commercially available or can be prepared using standard methodology.

Scheme 2.

(c) metal catalysed reaction between the amine (XIV) and a suitably substituted nitrobenzene compound (XXIV) wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, P represents a nitrogen protecting group (e.g. Boc, acetyl, trifluoroacetyl, benzyloxycarbonyl), and Z represents a leaving group such as bromo, iodo, chloro or triflate (Scheme 6). This process generates intermediates of formula (XXIII). Reduction of the nitro group, followed by cyclisation and deprotection as described hereinbefore provides the desired product (II) (Scheme 3). Compounds of formula (XXIV) and (XIV) are commercially available or can be prepared by standard methodology.

Scheme 3.

(XXlIl)

(d) metal catalysed reaction between the amine (XIV) and the protected aniline (XXV), wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, P and P' independently represent a nitrogen protecting group (e.g. Boc, acetyl, trifluoroacetyl, benzyloxycarbonyl), and Z represents a leaving group such as bromo, iodo, chloro or triflate, to give the intermediate (XXVI) (Scheme 4). Deprotection of the aniline followed by the same reaction sequence as in Scheme 3 affords the desired intermediate (II). Compounds of formula (XXV) are commercially available or can be prepared by known methodology e.g. halogenation ortho to the aniline group. The compound (XIV) can be prepared by known methodology.

Scheme 4.

The compound of formula (III) is commercially available.

Compounds of formula (IV) can be prepared by a number of different processes e.g.

(e) displacement of an ortho-fluoro or ortho-chloro nitrobenzene intermediate (XIII) with the amine (XXVII) to afford compound (XXVIII) wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, and Q is hydrogen or C_1- ₆alkyl, followed by reduction of the nitro group using standard conditions e.g. hydrogenation over palladium or Raney nickel (Scheme 5). Compounds of formula (XIII) are commercially available or can be prepared by standard methodology.

Scheme 5.

(f) metal catalysed reaction of the amine (XXVII) with the ortho substituted nitrobenzene (XXIX) to afford compound (XXVIII) wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶ (Scheme 6) and Q is hydrogen or C_1- ₆alkyl, followed by the same reactions as illustrated in Scheme 5. Compounds of formula (XXIX) are commercially available or can be prepared by standard methodology.

Scheme 6.

(g) metal catalysed reaction of the amine (XXVII) with the protected aniline derivative (XXV), wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, Q is hydrogen or Ci_-6alkyl, and P represents a nitrogen protecting group (such as acetyl, trifluoroacetyl, Boc, phthalimide), to afford compound (XXXI) (Scheme 7) followed by deprotection of the aniline group. Compounds of formula (XXV) are commercially available or can be prepared by standard methodology.

Scheme 7

Compounds of formula (V) are commercially available e.g. carbonyl diimidazole, phosgene, phosgene solution in toluene, diphosgene, triphosgene, phenyl chloroformate, diethyl carbonate.

Compounds of formula (Vl) can be prepared by a variety of processes e.g. urea formation can be achieved as shown in Scheme 8 by:

• combining the two amines (XXXIV) and (XXVII) with phosgene or a phosgene equivalent using standard conditions Phosgene equivalents include carbonyl diimidazole, diphosgene, triphosgene, phenyl chloroformate;

• reacting the amine (XXVII) with the isocyanate (XXXV); or

• reacting the amine (XXXIV) with the isocyanate (XXXVI).

Both isocyanates (XXXV) and (XXXVI) can be prepared from the corresponding amines using standard methodology for isocyanate formation wherein R is a group R as previously defined, or a group convertible to R, R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, and Q is hydrogen or Ci_-6alkyl. Scheme 8.

+ phosgene equivalent

(XXVIl)

(XXVIl)

Palladium and copper catalysts (VII) are commercially available or can be prepared as described in the literature (see references in Process C).

Compounds of formula (X) wherein R is a group R as previously defined, or a group convertible to R , R⁴ is a group R⁴ as previously defined, or a group convertible to R⁴, R⁵ is a group R⁵ as previously defined, or a group convertible to R⁵, R⁶ is a group R⁶ as previously defined, or a group convertible to R⁶, and Q is hydrogen or C_1-6alkyl, can be prepared as shown in Scheme 9. Reductive alkylation of an anthranilic acid or ester (XVII) with the ketone (XXXII), followed if appropriate by hydrolysis of the ester group.

Scheme 9.

Compounds of formula (Xl) are commercially available or can be prepared by literature processes.

Compounds of formula (XII) can be prepared as shown in Scheme 10, by reductive alkylation of (XXXVII) where R is a group R as previously defined, or a group convertible to R , Z' represents Z or a group convertible to Z with the ketone (III), and Q is H. Conversion of a Z' = hydroxy group to Z = chloro or bromo can be accomplished using standard methodology e.g. treatment with thionyl chloride or triphenylphosphine/carbon tetrabromide.

Scheme 10.

(XXXVIl) (III)

(XII)

The compound (XXVII) where Q is H can be prepared as shown in Scheme 11. Reductive alkylation of the amine (XXXVIII) where R is a group R as previously defined, or a group convertible to R , with tetrahydropyran-4-one (III) using for example sodium triacetoxyborohydride in dichloroethane provides the intermediate (XXXIX) which is deprotected using HCI in ethanol or trifluoroacetic acid to afford the primary amine (XXVII).

Scheme 11.

(XXXVlIl) (III)

(XXXIX) (XXVIl)

In one embodiment, the group R⁴ in the above described processes is the group R⁴ as hereinbefore defined.

In one embodiment, the group R⁵ in the above described processes is the group R⁵ as hereinbefore defined.

In one embodiment, the group R⁶ in the above described processes is the group R⁶ as hereinbefore defined.

In one embodiment, the group R' in the above described processes is the group R as hereinbefore defined. Compounds of the present invention are M₁ receptor agonists. Selective M₁ receptor agonists are said to be useful to ameliorate positive and cognitive symptoms of psychotic disorders such as schizophrenia, schizo-affective disorders, schizophreniform diseases, psychotic depression, mania, acute mania, paranoid and delusional disorders, and cognitive impairment including memory disorders such as Alzheimer's disease without peripheral cholinergic side effects mediated predominantly through M₂ and M₃ receptors. M₁ receptor agonists may also be suitable for combination with other typical and atypical antipsychotics and other actives such as mood stabilisers, antidepressants, anxiolytics, drugs for extrapyramidal side effects and cognitive enhancers, to provide improved treatment of psychotic disorders.

Thus in a further aspect, the invention provides a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof for use in therapy.

In another aspect, the invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof for use in the treatment of a condition wherein agonism of a muscarinic M₁ receptor would be beneficial.

The terms describing the indications used herein are classified in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, published by the American Psychiatric Association (DSM-IV) and/or the International Classification of Diseases, 10th Edition (ICD-10). Treatment of the various subtypes of the disorders mentioned herein are contemplated as part of the present invention. Numbers in brackets after the listed diseases below refer to the classification code in DSM-IV.

Within the context of the present invention, the term psychotic disorder includes Schizophrenia including the subtypes Paranoid Type (295.30), Disorganised Type (295.10), Catatonic Type (295.20), Undifferentiated Type (295.90) and Residual Type (295.60); Schizophreniform Disorder (295.40); Schizoaffective Disorder (295.70) including the subtypes Bipolar Type and Depressive Type; Delusional Disorder (297.1 ) including the subtypes Erotomanic Type, Grandiose Type, Jealous Type, Persecutory Type, Somatic Type, Mixed Type and Unspecified Type; Brief Psychotic Disorder (298.8); Shared Psychotic Disorder (297.3); Psychotic Disorder Due to a General Medical Condition including the subtypes With Delusions and With Hallucinations; Substance-Induced Psychotic Disorder including the subtypes With Delusions (293.81 ) and With Hallucinations (293.82); and Psychotic Disorder Not Otherwise Specified (298.9);

Other conditions wherein agonism of the M₁ receptor would be beneficial in their treatment include: Depression and mood disorders including Major Depressive Episode, Manic Episode, Mixed Episode and Hypomanic Episode; Depressive Disorders including Major Depressive Disorder, Dysthymic Disorder (300.4), Depressive Disorder Not Otherwise Specified (31 1 ); Bipolar Disorders including Bipolar I Disorder, Bipolar Il Disorder (Recurrent Major Depressive Episodes with Hypomanic Episodes) (296.89), Cyclothymic Disorder (301.13) and Bipolar Disorder Not Otherwise Specified (296.80); Other Mood Disorders including Mood Disorder Due to a General Medical Condition (293.83) which includes the subtypes With Depressive Features, With Major Depressive-like Episode, With Manic Features and With Mixed Features), Substance-Induced Mood Disorder (including the subtypes With Depressive Features, With Manic Features and With Mixed Features) and Mood Disorder Not Otherwise Specified (296.90);

Anxiety disorders including Social Anxiety Disorder, Panic Attack, Agoraphobia, Panic Disorder, Agoraphobia Without History of Panic Disorder (300.22), Specific Phobia (300.29) including the subtypes Animal Type, Natural Environment Type, Blood-lnjection- Injury Type, Situational Type and Other Type), Social Phobia (300.23), Obsessive- Compulsive Disorder (300.3), Posttraumatic Stress Disorder (309.81 ), Acute Stress Disorder (308.3), Generalized Anxiety Disorder (300.02), Anxiety Disorder Due to a General Medical Condition (293.84), Substance-Induced Anxiety Disorder and Anxiety Disorder Not Otherwise Specified (300.00);

Substance-related disorders including Substance Use Disorders such as Substance Dependence, Substance Craving and Substance Abuse; Substance-Induced Disorders such as Substance Intoxication, Substance Withdrawal, Substance-Induced Delirium, Substance-Induced Persisting Dementia, Substance-Induced Persisting Amnestic Disorder, Substance-Induced Psychotic Disorder, Substance-Induced Mood Disorder, Substance-Induced Anxiety Disorder, Substance-Induced Sexual Dysfunction, Substance- Induced Sleep Disorder and Hallucinogen Persisting Perception Disorder (Flashbacks); Alcohol-Related Disorders such as Alcohol Dependence (303.90), Alcohol Abuse (305.00), Alcohol Intoxication (303.00), Alcohol Withdrawal (291.81 ), Alcohol Intoxication Delirium, Alcohol Withdrawal Delirium, Alcohol-Induced Persisting Dementia, Alcohol- Induced Persisting Amnestic Disorder, Alcohol-Induced Psychotic Disorder, Alcohol- Induced Mood Disorder, Alcohol-Induced Anxiety Disorder, Alcohol-Induced Sexual Dysfunction, Alcohol-Induced Sleep Disorder and Alcohol-Related Disorder Not Otherwise Specified (291.9); Amphetamine (or Amphetamine-I_ike)-Related Disorders such as Amphetamine Dependence (304.40), Amphetamine Abuse (305.70), Amphetamine Intoxication (292.89), Amphetamine Withdrawal (292.0), Amphetamine Intoxication Delirium, Amphetamine Induced Psychotic Disorder, Amphetamine-Induced Mood Disorder, Amphetamine-Induced Anxiety Disorder, Amphetamine-Induced Sexual Dysfunction, Amphetamine-Induced Sleep Disorder and Amphetamine-Related Disorder Not Otherwise Specified (292.9); Caffeine Related Disorders such as Caffeine Intoxication (305.90), Caffeine-Induced Anxiety Disorder, Caffeine-Induced Sleep Disorder and Caffeine-Related Disorder Not Otherwise Specified (292.9); Cannabis-Related Disorders such as Cannabis Dependence (304.30), Cannabis Abuse (305.20), Cannabis Intoxication (292.89), Cannabis Intoxication Delirium, Cannabis-lnduced Psychotic Disorder, Cannabis-lnduced Anxiety Disorder and Cannabis-Related Disorder Not Otherwise Specified (292.9); Cocaine-Related Disorders such as Cocaine Dependence (304.20), Cocaine Abuse (305.60), Cocaine Intoxication (292.89), Cocaine Withdrawal (292.0), Cocaine Intoxication Delirium, Cocaine-Induced Psychotic Disorder, Cocaine-Induced Mood Disorder, Cocaine-Induced Anxiety Disorder, Cocaine-Induced Sexual Dysfunction, Cocaine-Induced Sleep Disorder and Cocaine-Related Disorder Not Otherwise Specified (292.9); Hallucinogen-Related Disorders such as Hallucinogen Dependence (304.50), Hallucinogen Abuse (305.30), Hallucinogen Intoxication (292.89), Hallucinogen Persisting Perception Disorder (Flashbacks) (292.89), Hallucinogen Intoxication Delirium, Hallucinogen-Induced Psychotic Disorder, Hallucinogen-Induced Mood Disorder, Hallucinogen-Induced Anxiety Disorder and Hallucinogen-Related Disorder Not Otherwise Specified (292.9); Inhalant-Related Disorders such as Inhalant Dependence (304.60), Inhalant Abuse (305.90), Inhalant Intoxication (292.89), Inhalant Intoxication Delirium, Inhalant-Induced Persisting Dementia, Inhalant-Induced Psychotic Disorder, Inhalant- Induced Mood Disorder, Inhalant-Induced Anxiety Disorder and Inhalant-Related Disorder Not Otherwise Specified (292.9); Nicotine-Related Disorders such as Nicotine Dependence (305.1 ), Nicotine Withdrawal (292.0) and Nicotine-Related Disorder Not Otherwise Specified (292.9); Opioid-Related Disorders such as Opioid Dependence (304.00), Opioid Abuse (305.50), Opioid Intoxication (292.89), Opioid Withdrawal (292.0), Opioid Intoxication Delirium, Opioid-lnduced Psychotic Disorder, Opioid-lnduced Mood Disorder, Opioid-lnduced Sexual Dysfunction, Opioid-lnduced Sleep Disorder and Opioid- Related Disorder Not Otherwise Specified (292.9); Phencyclidine (or Phencyclidine-Like)- Related Disorders such as Phencyclidine Dependence (304.60), Phencyclidine Abuse (305.90), Phencyclidine Intoxication (292.89), Phencyclidine Intoxication Delirium, Phencyclidine-lnduced Psychotic Disorder, Phencyclidine-lnduced Mood Disorder, Phencyclidine-lnduced Anxiety Disorder and Phencyclidine-Related Disorder Not Otherwise Specified (292.9); Sedative-, Hypnotic-, or Anxiolytic-Related Disorders such as Sedative, Hypnotic, or Anxiolytic Dependence (304.10), Sedative, Hypnotic, or Anxiolytic Abuse (305.40), Sedative, Hypnotic, or Anxiolytic Intoxication (292.89), Sedative, Hypnotic, or Anxiolytic Withdrawal (292.0), Sedative, Hypnotic, or Anxiolytic Intoxication Delirium, Sedative, Hypnotic, or Anxiolytic Withdrawal Delirium, Sedative-, Hypnotic-, or Anxiolytic-Persisting Dementia, Sedative-, Hypnotic-, or Anxiolytic- Persisting Amnestic Disorder, Sedative-, Hypnotic-, or Anxiolytic-lnduced Psychotic Disorder, Sedative-, Hypnotic-, or Anxiolytic-lnduced Mood Disorder, Sedative-, Hypnotic-, or Anxiolytic- lnduced Anxiety Disorder Sedative-, Hypnotic-, or Anxiolytic-lnduced Sexual Dysfunction, Sedative-, Hypnotic-, or Anxiolytic-lnduced Sleep Disorder and Sedative-, Hypnotic-, or Anxiolytic-Related Disorder Not Otherwise Specified (292.9); Polysubstance-Related Disorder such as Polysubstance Dependence (304.80); and Other (or Unknown) Substance-Related Disorders such as Anabolic Steroids, Nitrate Inhalants and Nitrous Oxide;

Sleep disorders including primary sleep disorders such as Dyssomnias such as Primary Insomnia (307.42), Primary Hypersomnia (307.44), Narcolepsy (347), Breathing-Related Sleep Disorders (780.59), Circadian Rhythm Sleep Disorder (307.45) and Dyssomnia Not Otherwise Specified (307.47); primary sleep disorders such as Parasomnias such as Nightmare Disorder (307.47), Sleep Terror Disorder (307.46), Sleepwalking Disorder (307.46) and Parasomnia Not Otherwise Specified (307.47); Sleep Disorders Related to Another Mental Disorder such as Insomnia Related to Another Mental Disorder (307.42) and Hypersomnia Related to Another Mental Disorder (307.44); Sleep Disorder Due to a General Medical Condition; and Substance-Induced Sleep Disorder including the subtypes Insomnia Type, Hypersomnia Type, Parasomnia Type and Mixed Type;

Eating disorders such as Anorexia Nervosa (307.1 ) including the subtypes Restricting Type and Binge-Eating/Purging Type; Bulimia Nervosa (307.51 ) including the subtypes Purging Type and Nonpurging Type; Obesity; Compulsive Eating Disorder; and Eating Disorder Not Otherwise Specified (307.50);

Autistic Disorder (299.00); Attention-Deficit /Hyperactivity Disorder including the subtypes Attention-Deficit /Hyperactivity Disorder Combined Type (314.01 ), Attention-Deficit /Hyperactivity Disorder Predominantly Inattentive Type (314.00), Attention-Deficit /Hyperactivity Disorder Hyperactive-Impulse Type (314.01 ) and Attention-Deficit /Hyperactivity Disorder Not Otherwise Specified (314.9); Hyperkinetic Disorder; Disruptive Behaviour Disorders such as Conduct Disorder including the subtypes childhood-onset type (321.81 ), Adolescent-Onset Type (312.82) and Unspecified Onset (312.89), Oppositional Defiant Disorder (313.81 ) and Disruptive Behaviour Disorder Not Otherwise Specified; and Tic Disorders such as Tourette's Disorder (307.23);

Personality Disorders including the subtypes Paranoid Personality Disorder (301.0), Schizoid Personality Disorder (301.20), Schizotypal Personality Disorder (301 ,22), Antisocial Personality Disorder (301.7), Borderline Personality Disorder (301 ,83), Histrionic Personality Disorder (301.50), Narcissistic Personality Disorder (301 ,81 ), Avoidant Personality Disorder (301.82), Dependent Personality Disorder (301.6), Obsessive-Compulsive Personality Disorder (301.4) and Personality Disorder Not Otherwise Specified (301.9); and

Sexual dysfunctions including Sexual Desire Disorders such as Hypoactive Sexual Desire Disorder (302.71 ), and Sexual Aversion Disorder (302.79); sexual arousal disorders such as Female Sexual Arousal Disorder (302.72) and Male Erectile Disorder (302.72); orgasmic disorders such as Female Orgasmic Disorder (302.73), Male Orgasmic Disorder (302.74) and Premature Ejaculation (302.75); sexual pain disorder such as Dyspareunia (302.76) and Vaginismus (306.51 ); Sexual Dysfunction Not Otherwise Specified (302.70); paraphilias such as Exhibitionism (302.4), Fetishism (302.81 ), Frotteurism (302.89), Pedophilia (302.2), Sexual Masochism (302.83), Sexual Sadism (302.84), Transvestic Fetishism (302.3), Voyeurism (302.82) and Paraphilia Not Otherwise Specified (302.9); gender identity disorders such as Gender Identity Disorder in Children (302.6) and Gender Identity Disorder in Adolescents or Adults (302.85); and Sexual Disorder Not Otherwise Specified (302.9).

The compounds of formula (I) may also be useful for the enhancement of cognition, including both the treatment of cognitive impairment on its own and the treatment of cognition impairment in other diseases such as schizophrenia, bipolar disorder, depression, other psychiatric disorders and psychotic conditions associated with cognitive impairment. Where cognitive impairment results from a treatment of a disease, M₁ agonists may be beneficial. For example, when the treatment of epilepsy with anticonvulsants results in cognitive impairment, an M₁ agonist may be useful for the alleviation or treatment of the cognitive impairment.

Within the context of the present invention, the term cognitive impairment includes, for example, impairment of cognitive functions including attention, orientation, learning disorders, memory (i.e. memory disorders, amnesia, amnesic disorders, transient global amnesia syndrome and age-associated memory impairment) and language function; cognitive impairment as a result of stroke, Alzheimer's disease, Huntington's disease, Pick disease, Aids-related dementia or other dementia states such as Multiinfarct dementia, alcoholic dementia, hypotiroidism-related dementia, and dementia associated to other degenerative disorders such as cerebellar atrophy and amyotropic lateral sclerosis; other acute or sub-acute conditions that may cause cognitive decline such as delirium or depression (pseudodementia states) trauma, head trauma, age related cognitive decline, stroke, neurodegeneration, drug-induced states, neurotoxic agents, mild cognitive impairment, age related cognitive impairment, autism related cognitive impairment, Down's syndrome, cognitive deficit related to psychosis, and post-electroconvulsive treatment related cognitive disorders; and dyskinetic disorders such as Parkinson's disease, neuroleptic-induced parkinsonism, and tardive dyskinesias.

Compounds of formula (I) or pharmaceutically accepatble salts thereof may also be used as memory and/or cognition enhancers in healthy humans with no cognitive and/or memory deficit.

In another aspect, the invention provides a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof for use in the treatment of a psychotic disorder. In one embodiment, the invention provides a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof for use in the treatment of schizophrenia. The invention also provides a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof for use in the treatment of cognitive impairment.

In another aspect, the invention provides the use of a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for the treatment of a condition wherein agonism of the M₁ receptor would be beneficial.

In another aspect, the invention provides the use of a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for the treatment of a psychotic disorder. In one embodiment, the invention provides the use of a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for the treatment of schizophrenia.

In another aspect, the invention provides a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof in the treatment of a psychotic disorder. In one embodiment, the invention provides a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof for the treatment of schizophrenia.

The invention also provides the use of a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for the treatment of cognitive impairment.

The invention also provides a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof for the treatment of cognitive impairment.

In another aspect, the invention provides a method of treating a condition where agonism of the M₁ receptor would be beneficial, which comprises administering to a mammal in need thereof an effective amount of a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof. In one embodiment, the mammal is a human.

In another aspect, the invention provides a method of treating a psychotic disorder which comprises administering to a mammal in need thereof an effective amount of a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof. In one embodiment, the invention provides a method of treating schizophrenia, which comprises administering to a mammal in need thereof an effective amount of a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof. In one embodiment, the mammal is a human. The invention also provides a method of treating cognitive impairment, which comprises administering to a mammal in need thereof an effective amount of a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof. In one embodiment, the mammal is a human.

The compounds of formula (I) and pharmaceutically acceptable salts thereof may also be suitable for combination with other actives, such as typical and atypical antipsychotics, mood stabilisers, antidepressants, anxiolytics, drugs for extrapyrimidal side effects and cognitive enhancers to provide improved treatment of psychotic disorders.

The combination therapies of the invention are, for example, administered adjunctively. By adjunctive administration is meant the coterminous or overlapping administration of each of the components in the form of separate pharmaceutical compositions or devices. This regime of therapeutic administration of two or more therapeutic agents is referred to generally by those skilled in the art and herein as adjunctive therapeutic administration; it is also known as add-on therapeutic administration. Any and all treatment regimes in which a patient receives separate but coterminous or overlapping therapeutic administration of the compounds of formula (I) or a pharmaceutically acceptable salt thereof and at least one antipsychotic agent, a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects or a cognitive enhancer are within the scope of the current invention. In one embodiment of adjunctive therapeutic administration as described herein, a patient is typically stabilised on a therapeutic administration of one or more of the components for a period of time and then receives administration of another component. The compounds of formula (I) or a pharmaceutically acceptable salt thereof may be administered as adjunctive therapeutic treatment to patients who are receiving administration of at least one antipsychotic agent, a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects or a cognitive enhancer, but the scope of the invention also includes the adjunctive therapeutic administration of at least one antipsychotic agent, a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects or a cognitive enhancer to patients who are receiving administration of compounds of formula (I) or a pharmaceutically acceptable salt thereof.

The combination therapies of the invention may also be administered simultaneously. By simultaneous administration is meant a treatment regime wherein the individual components are administered together, either in the form of a single pharmaceutical composition or device comprising or containing both components, or as separate compositions or devices, each comprising one of the components, administered simultaneously. Such combinations of the separate individual components for simultaneous combination may be provided in the form of a kit-of-parts. In a further aspect therefore, the invention provides a method of treatment of a psychotic disorder by adjunctive therapeutic administration of compounds of formula (I) or a pharmaceutically acceptable salt thereof to a patient receiving therapeutic administration of at least one antipsychotic agent. In a further aspect, the invention provides the use of compounds of formula (I) or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of at least one antipsychotic agent. In a further aspect, the invention provides compounds of formula (I) or a pharmaceutically acceptable salt thereof for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of at least one antipsychotic agent. The invention further provides compounds of formula (I) or a pharmaceutically acceptable salt thereof for use for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of at least one antipsychotic agent.

In a further aspect, the invention provides a method of treatment of a psychotic disorder by adjunctive therapeutic administration of at least one antipsychotic agent to a patient receiving therapeutic administration of compounds of formula (I) or a pharmaceutically acceptable salt thereof. In a further aspect, the invention provides the use of at least one antipsychotic agent in the manufacture of a medicament for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of compounds of formula (I) or a pharmaceutically acceptable salt thereof. In a further aspect, the invention provides at least one antipsychotic agent for adjunctive therapeutic administration for the treatment of a psychotic disorder in a pateient recieving therapeutic administration of compounds of formula (I) or a pharmaceutically acceptable salt thereof. The invention further provides at least one antipsychotic agent for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of compounds of formula (I) or a pharmaceutically acceptable salt thereof.

In a further aspect, the invention provides a method of treatment of a psychotic disorder by simultaneous therapeutic administration of compounds of formula (I) or a pharmaceutically acceptable salt thereof in combination with at least one antipsychotic agent. The invention further provides the use of a combination of compounds of formula (I) or a pharmaceutically acceptable salt thereof and at least one antipsychotic agent in the manufacture of a medicament for simultaneous therapeutic administration in the treatment of a psychotic disorder. The invention further provides a combination of compounds of formula (I) or a pharmaceutically acceptable salt thereof and at least one antipsycotic agent for simultaneous therapeutic administration in the treatment of a psychotic disorder. The invention further provides the use of compounds of formula (I) or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for simultaneous therapeutic administration with at least one antipsychotic agent in the treatment of a psychotic disorder. The invention further provides compounds of formula (I) or a pharmaceutically acceptable salt thereof for use for simultaneous therapeutic administration with at least one antipsychotic agent in the treatment of a psychotic disorder. The invention further provides the use of at least one antipsychotic agent in the manufacture of a medicament for simultaneous therapeutic administration with compounds of formula (I) or a pharmaceutically acceptable salt thereof in the treatment of a psychotic disorder. The invention further provides at least one antipsychotic agent for simultaneous therapeutic administration with compounds of formula (I) or a pharmaceutically acceptable salt thereof in the treatment of a psychotic disorder.

In a further aspect, the invention provides a kit-of-parts for use in the treatment of a psychotic disorder comprising a first dosage form comprising compounds of formula (I) or a pharmaceutically acceptable salt thereof and one or more further dosage forms each comprising an antipsychotic agent for simultaneous therapeutic administration.

In another aspect, the invention provides a method of treatment of a psychotic disorder by adjunctive therapeutic administration of a compound of the present invention to a patient receiving therapeutic administration of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer.

In a further aspect, the invention provides the use of a compound of the present invention in the manufacture of a medicament for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer.

The invention also provides a compound of the present invention for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer.

The invention also provides the use of a compound of the present invention in adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer.

The invention further provides the use of a compound of the present invention for use for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer.

In a further aspect, the invention provides a method of treatment of a psychotic disorder by adjunctive therapeutic administration of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer to a patient receiving therapeutic administration of a compound of the present invention.

In a further aspect, the invention provides the use of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer in the manufacture of a medicament for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of a compound of the present invention.

The invention also provides an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of a compound of the present invention

The invention also provides the use of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer for adjunctive therapeutic administration for the treatment of a psychotic disorder in a patient receiving therapeutic administration of a compound of the present invention

In a further aspect, the invention provides a method of treatment of a psychotic disorder by simultaneous therapeutic administration of a compound of the present invention in combination with an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer.

The invention further provides the use of a combination of a compound of the present invention and an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer in the manufacture of a medicament for simultaneous therapeutic administration in the treatment of a psychotic disorder.

The invention further provides a combination of a compound of the present invention and an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer for simultaneous therapeutic administration for the treatment of a psychotic disorder.

The invention further provides the use of a combination of a compound of the present invention and an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer for simultaneous therapeutic administration in the treatment of a psychotic disorder.

The invention further provides the use of a compound of the present invention in the manufacture of a medicament for simultaneous therapeutic administration with an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer in the treatment of a psychotic disorder.

The invention further provides a compound of the present invention for simultaneous therapeutic administration with an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer for the treatment of a psychotic disorder.

The invention further provides the use of a compound of the present invention for simultaneous therapeutic administration with an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer in the treatment of a psychotic disorder.

The invention further provides a compound of the present invention for use for simultaneous therapeutic administration with an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer in the treatment of a psychotic disorder.

The invention further provides the use of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer in the manufacture of a medicament for simultaneous therapeutic administration with a compound of the present invention in the treatment of a psychotic disorder.

The invention further provides an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer for simultaneous therapeutic administration with a compound of the present invention for the treatment of a psychotic disorder. The invention further provides the use of an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer for simultaneous therapeutic administration with a compound of the present invention in the treatment of a psychotic disorder.

In a further aspect, the invention provides a kit-of-parts for use in the treatment of a psychotic disorder comprising a first dosage form comprising a compound of the present invention and one or more further dosage forms each comprising an active ingredient selected from the group consisting of: a mood stabiliser, an antidepressant, an anxiolytic, a drug for extrapyrimidal side effects and a cognitive enhancer for simultaneous therapeutic administration.

In one embodiment, the patient is a human.

Examples of antipsychotic drugs that may be useful in the present invention include, but are not limited to: sodium channel blockers; mixed 5HT/dopamine receptor antagonists; mGluR5 positive modulators; D3 antagonists; 5HT6 angatonists; nicotinic alpha-7 modulators; glycine transporter GIyTI inhibitors; D2 partial agonist/D3 antanogist/H3 antagonists; AMPA modulators; NK3 antagonists such as osanetant and talnetant; an atypical antipsychotic, for example clozapine, olanzapine, risperidone, quetiapine, aripirazole, ziprasidone and amisulpride; butyrophenones, such as haloperidol, pimozide, and droperidol; phenothiazines, such as chlorpromazine, thioridazine, mesoridazine, trifluoperazine, perphenazine, fluphenazine, thiflupromazine, prochlorperazine, and acetophenazine; thioxanthenes, such as thiothixene and chlorprothixene; thienobenzodiazepines; dibenzodiazepines; benzisoxazoles; dibenzothiazepines; imidazolidinones; benzisothiazolyl-piperazines; triazine such as lamotrigine; dibenzoxazepines, such as loxapine; dihydroindolones, such as molindone; aripiprazole; and derivatives thereof that have antipsychotic activity.

Examples of tradenames and suppliers of selected antipsychotic drugs that may be suitable for use in the present invention are as follows : clozapine (available under the tradename CLOZARIL®, from Mylan, Zenith Goldline, UDL, Novartis); olanzapine (available under the tradename ZYPREXA®, from Lilly); ziprasidone (available under the tradename GEODON®, from Pfizer); risperidone (available under the tradename RISPERDAL®, from Janssen); quetiapine fumarate (available under the tradename SEROQUEL®, from AstraZeneca); sertindole (available under the tradename SERLECT®); amisulpride (available under the tradename SOLION®, from Sanofi- Synthelabo); haloperidol (available under the tradename HALDOL®, from Ortho-McNeil); haloperidol decanoate (available under the tradename HALDOL decanoate®); haloperidol lactate (available under the tradenames HALDOL® and INTENSOL®); chlorpromazine (available under the tradename THORAZINE®, from SmithKline Beecham (GSK)); fluphenazine (available under the tradename PROLIXIN®, from Apothecon, Copley, Schering, Teva, and American Pharmaceutical Partners, Pasadena); fluphenazine decanoate (available under the tradename PROLIXIN decanoate®); fluphenazine enanthate (available under the tradename PROLIXIN®); fluphenazine hydrochloride (available under the tradename PROLIXIN®); thiothixene (available under the tradename NAVANE®, from Pfizer); thiothixene hydrochloride (available under the tradename NAVANE®); trifluoperazine (10-[3-(4-methyl-1-piperazinyl)propyl]-2-

(trifluoromethyl)phenothiazine dihydrochloride, available under the tradename STELAZINE®, from SmithKline Beckman); perphenazine (available under the tradename TRILAFON®, from Schering); perphenazine and amitriptyline hydrochloride (available under the tradename ETRAFON TRILAFON®); thioridazine (available under the tradename MELLARIL®; from Novartis, Roxane, HiTech, Teva, and Alpharma); molindone (available under the tradename MOBAN®, from Endo); molindone hydrochloride (available under the tradename MOBAN®); loxapine (available under the tradename LOXITANE®; from Watson); loxapine hydrochloride (available under the tradename LOXITANE®); and loxapine succinate (available under the tradename LOXITANE®). Furthermore, benperidol (Glianimon®), perazine (Taxilan®) or melperone (Eunerpan®)) may be used.

Other suitable antipsychotic drugs include promazine (available under the tradename SPARINE®), triflurpromazine (available under the tradename VESPRIN®), chlorprothixene (available under the tradename TARACTAN®), droperidol (available under the tradename INAPSINE®), acetophenazine (available under the tradename

TINDAL®;), prochlorperazine (available under the tradename COMPAZINE®), methotrimeprazine (available under the tradename NOZI NAN®), pipotiazine (available under the tradename PIPOTRIL®), iloperidone, pimozide and flupenthixol.

The antipsychotic drugs listed above by Tradename may also be available from other suppliers under a different Tradename.

In one further aspect of the invention, suitable antipsychotic agents include olanzapine, risperidone, quetiapine, amisulpride, aripiprazole, haloperidol, clozapine, olanzepine, ziprasidone, talnetant and osanetant.

Mood stabilisers which may be used in the therapy of the present invention include lithium, sodium valproate/valproic acid/divalproex, carbamazepine, lamotrigine, gabapentin, topiramate, oxcarbazepine and tiagabine.

Antidepressant drugs which may be used in the therapy of the present invention include serotonin antagonists, CRF-1 antagonists, Cox-2 inhibitor/SSRI dual antagonists; dopamine/noradrenaline/serotonin triple reuptake inhibitors; NK1 antagonists; NK1 and NK2 dual antagonists; NK1/SSRI dual antagonists; NK2 antagonists; serotonin agonists (such as rauwolscine, yohimbine and metoclopramide); serotonin reuptake inhibitors (such as citalopram, escitalopram, fluoxetine, fluvoxamine, femoxetine, indalpine, zimeldine, paroxetine and sertraline); dual serotonin/noradrenaline reuptake inhibitors (such as venlafaxine, reboxetine, duloxetine and milnacipran); Noradrenaline reuptake inhibitors (such as reboxetine); tricyclic antidepressants (such as amitriptyline, clomipramine, imipramine, maprotiline, nortriptyline and trimipramine); monoamine oxidase inhibitors (such as isocarboxazide, moclobemide, phenelzine and tranylcypromine); 5HT3 antagonists (such as example ondansetron and granisetron); and others (such as bupropion, amineptine, radafaxine, mianserin, mirtazapine, nefazodone and trazodone).

Anxiolytics which may be used in the therapy of the present invention include V1 b antagonists, 5HT7 antagonists and benzodiazepines such as alprazolam and lorazepam.

Drugs for extrapyramidal side effects which may be used in the therapy of the present invention include anticholinergics (such as benztropine, biperiden, procyclidine and trihexyphenidyl), antihistamines (such as diphenhydramine) and dopaminergics (such as amantadine).

Cognitive enhancers which may be used in the therapy of the present invention include example cholinesterase inhibitors (such as tacrine, donepezil, rivastigmine and galantamine), H3 antagonists and muscarinic M₁ agonists (such as cevimeline).

For use in medicine, the compounds of the present invention are usually administered as a standard pharmaceutical composition. The present invention therefore provides in a further aspect a pharmaceutical composition comprising a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier. The pharmaceutical composition can be for use in the treatment of any of the conditions described herein. In a further aspect, the invention provides a process for preparing a pharmaceutical composition, the process comprising mixing a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof and one or more pharmaceutically acceptable carriers. In a further aspect, the invention provides a pharmaceutical composition comprising a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof in combination with at least 1 antipsychotic, and one or more pharmaceutically acceptable carriers. In a further aspect, the invention provides a process for preparing a pharmaceutical composition, the process comprising mixing a compound of formula (I) as hereinbefore described or a pharmaceutically acceptable salt thereof, at least 1 antipsychotic, and one or more pharmaceutically acceptable carriers.

The compounds of the invention may be administered by any convenient method, for example by oral, parenteral (e.g. intravenous), buccal, sublingual, nasal, rectal or transdermal administration and the pharmaceutical compositions adapted accordingly. The compounds of the invention which are active when given orally can be formulated as liquids or solids, for example syrups, suspensions or emulsions, tablets, capsules and lozenges.

A liquid formulation will generally consist of a suspension or solution of the compound or salt in a suitable liquid carrier(s) for example an aqueous solvent such as water, ethanol or glycerine, or a non-aqueous solvent, such as polyethylene glycol or an oil. The formulation may also contain a suspending agent, preservative, flavouring or colouring agent.

A composition in the form of a tablet can be prepared using any suitable pharmaceutical carrier(s) routinely used for preparing solid formulations. Examples of such carriers include magnesium stearate, starch, lactose, sucrose and cellulose.

A composition in the form of a capsule can be prepared using routine encapsulation procedures. For example, pellets containing the active ingredient can be prepared using standard carriers and then filled into a hard gelatin capsule; alternatively, a dispersion or suspension can be prepared using any suitable pharmaceutical carrier(s), for example aqueous gums, celluloses, silicates or oils and the dispersion or suspension then filled into a soft gelatin capsule.

Typical parenteral compositions consist of a solution or suspension of the compound or salt in a sterile aqueous carrier or parenterally acceptable oil, for example polyethylene glycol, polyvinyl pyrrolidone, lecithin, arachis oil or sesame oil. Alternatively, the solution can be lyophilised and then reconstituted with a suitable solvent just prior to administration.

Compositions for nasal administration may conveniently be formulated as aerosols, drops, gels and powders. Aerosol formulations typically comprise a solution or fine suspension of the active substance in a pharmaceutically acceptable aqueous or non-aqueous solvent and are usually presented in single or multidose quantities in sterile form in a sealed container, which can take the form of a cartridge or refill for use with an atomising device.

Alternatively the sealed container may be a unitary dispensing device such as a single dose nasal inhaler or an aerosol dispenser fitted with a metering valve which is intended for disposal once the contents of the container have been exhausted. Where the dosage form comprises an aerosol dispenser, it will contain a propellant which can be a compressed gas such as compressed air or an organic propellant such as a fluorochloro- hydrocarbon. The aerosol dosage forms can also take the form of a pump-atomiser. Compositions suitable for buccal or sublingual administration include tablets, lozenges and pastilles, wherein the active ingredient is formulated with a carrier such as sugar and acacia, tragacanth, or gelatin and glycerin.

Compositions for rectal administration are conveniently in the form of suppositories containing a conventional suppository base such as cocoa butter.

Compositions suitable for transdermal administration include ointments, gels and patches. The composition may be in unit dose form such as a tablet, capsule or ampoule.

Each dosage unit for oral administration contains, for example, from 1 to 250 mg (and for parenteral administration contains, for example, from 0.1 to 25 mg) of a compound of the formula (I) or a pharmaceutically acceptable salt thereof calculated as the free base.

It will be appreciated that the precise dose administered will depend on the age and condition of the patient and the frequency and route of administration and will be at the ultimate discretion of the attendant physician.

The antipsychotic agent component or components used in the adjunctive therapy of the present invention may also be administered in their basic or acidic forms as appropriate or, where appropriate, in the form of a pharmaceutically acceptable salt or other derivative. All solvates and all alternative physical forms of the antipsychotic agent or agents or their salts or derivatives as described herein, including but not limited to alternative crystalline forms, amorphous forms and polymorphs, are also within the scope of this invention. In the case of the antipsychotic agent or agents, the forms and derivatives are, for example, those which are approved for therapeutic administration as monotherapies, including those mentioned above, but all references to antipsychotic agents herein include all salts or other derivatives thereof, and all solvates and alternative physical forms thereof.

For adjunctive therapeutic administration according to the invention, compounds of formula (I) or pharmaceutically acceptable salts thereof and the antipsychotic agent or agents or their salts, derivatives or solvates may each be administered in pure form, but each of the components will, for example, be formulated into any suitable pharmaceutically acceptable and effective composition which provides effective levels of the respective component in the body. The choice of the most appropriate pharmaceutical compositions for each component is within the skill of the art, and may be the same form or different forms for each of the components. Suitable formulations include, but are not limited to tablets, capsules, powders, granules, lozenges, suppositories, reconstitutable powders, or liquid preparations such as oral or sterile parenteral solutions or suspensions. For simultaneous administration as a combined composition of compounds of formula (I) and the antipsychotic agent or agents according to the invention, compounds of formula (I) or their pharmaceutically acceptable salts and the antipsychotic agent or agents and their salts, derivatives or solvates may be administered together in pure form, but the combined components will, for example, be formulated into any suitable pharmaceutically acceptable and effective composition which provides effective levels of each of the components in the body. The choice of the most appropriate pharmaceutical compositions for the combined components is within the skill of the art. Suitable formulations include, but are not limited to tablets, sub-lingual tablets, buccal compositions, capsules, powders, granules, lozenges, suppositories, reconstitutable powders, or liquid preparations such as oral or sterile parenteral solutions or suspensions.

In order to obtain consistency of adjunctive administration, the compositions of each of the components, or of the combination of the components is, for example, in the form of a unit dose.

The term "treatment" includes prophylaxis, where this is appropriate for the relevant condition(s).

Biological Test Methods

FLIPR experiments on IVh receptor to determine agonist/antagonist potency

Compounds of the invention were characterized in a functional assay to determine their ability to activate the intracellular calcium pathway in CHO cells with stable expression of human muscarinic receptors using FLIPR (Fluorometric Imaging Plate Reader) technology. Briefly, CHO-M1 cells were plated (15,000/well) and allowed to grow overnight at 37 degrees. Media was removed and 30μL loading buffer (HBSS with 2.5mM probenicid, 2μM Fluo-4, 500μM Brilliant Black, pH 7.4) was added. After incubation at 37 degrees for 90 minutes, 10μL of the assay buffer (HBSS with 2.5 mM probenecid, pH 7.4) containing test compounds was added to each well on the FLIPR instrument. Calcium response was monitored to determine agonism. Plates were then incubated for another 30 minutes before 10μL of assay buffer containing acetylcholine was added at an EC_8O, as the agonist challenge. Calcium response was then monitored again to determine compound's antagonism to acetylcholine. Concentration-response curves of both agonism and antagonism on M₁ receptors were performed for each compound. Results were imported into ActivityBase data analysis suite (ID Business Solution Inc., Parsippany, NJ) where the curves were analysed by non-linear curve fitting and the resulting pEC₅o/fpK, were calculated. The intrinsic activities of agonist compounds were calculated as percentage of maximum FLIPR response induced by acetylcholine added as control on the same compound plates, and converted to a fraction between 0 and 1 (i.e. calculated using a 100% max response from a fitted acetylcholine standard curve, containing multiple concentrations, as control). FLIPR experiments on M₁ receptor to determine agonist intrinsic activity To determine the intrinsic activities of M₁ agonist compounds, compounds of the invention were characterized in FLIPR experiments on CHO cells with transient expression of human muscarinic M₁ receptors. Briefly, CHO cells were transduced with M₁ BacMam virus (Ames, R S; Fornwald, J A; Nuthulaganti, P; Trill, J J; Foley, J J; Buckley, P T; Kost, T A; Wu, Z and Romanos, M A. (2004) Use of BacMam recombinant baculoviruses to support G protein-coupled receptor drug discovery. Receptors and Channels 10 (3-4): 99- 109) at a multiplicity of infection of 6. The virus to cell ratio was determined in separate experiments by functional titration to be most appropriate to measure intrinsic activities of partial agonists. After mixing with virus in suspension, cells were then plated (15,000/well) and allowed to grow overnight at 37 degrees.

Alternatively, cells were then frozen in 1 ml vials at a concentration of 4.8x10e7 cells/ml in 90% dialysed Foetal Bovine Serum, 10% DimethylSulphoxide at -140 degrees. Cells could then be thawed on the day prior to assay, plated (15,000/well) and allowed to grow overnight at 37 degrees.

The FLIPR experiment was carried out on the day following plating using the same protocol as described above for CHO-M₁ cells. Results were imported into ActivityBase data analysis suite where the curves were analysed by non-linear curve fitting and the resulting pEC₅₀ values were calculated. The intrinsic activities of agonist compounds were calculated as percentage of maximum FLIPR response induced by acetylcholine added as control on the same compound plates, and converted to a fraction between 0 and 1 (i.e. calculated using a 100% max response from a fitted acetylcholine standard curve, containing multiple concentrations, as control).

The exemplified compounds below were tested in the above assay and were each found to have an average pEC₅₀ value of > 5.0 at the muscarinic M₁ receptor, and intrinsic activity > 0.5.

FLIPR experiments on M_2-S receptor to determine receptor subtype selectivity

To determine selectivity of compounds of the invention against other muscarinic receptor subtypes, compounds were characterized in FLIPR experiments in CHO cells with stable expression of human muscarinic receptors, M₂, M₃, M₄ or M₅. In the case of M₂ and M₄ receptors, chimeric G-protein Gqi5 was also co-expressed to couple receptors to the calcium signaling pathway. Briefly, cells were plated (15,000/well) and allowed to grow overnight at 37 degrees. The FLIPR experiment was then carried out on the next day using the same protocol as described above for CHO-M1 cells. Results were imported into ActivityBase data analysis suite where the curves were analysed by non-linear curve fitting and the resulting pEC₅₀/fpK, values were calculated. The exemplified compounds below were tested in this assay and were found to be selective for the M₁ receptor over M₂, M₃, M₄ and M₅ receptors, with typical selectivity (ratio of pEC₅₀'s) of > 10-fold.

The invention is further illustrated by the following non-limiting examples. In the procedures that follow, after each starting material, reference to a Description by number is typically provided. This is provided merely for assistance to the skilled chemist.

The starting material may not necessarily have been prepared from the batch referred to.

MDAP refers to mass-directed automated purification using reverse phase chromatography on Ci₈ stationary phase eluted with acetonitrile/water/0.1% formic acid.

SCX refers to a sulfonic acid ion exchange resin supplied by Varian.

All reactions were either done under argon or can be done under argon, unless stated otherwise (for example hydrogenation reactions).

Proton Magnetic Resonance (NMR) spectra were recorded on Bruker Avance Il instruments at 300 or 400 MHz, chemical shifts are reported in ppm (δ) using the residual solvent line as internal standard. Splitting patterns are designed as s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; b, broad. The NMR spectra were recorded at temperature ranging from 25 to 9O⁰C; when more than one conformer was detected the chemical shifts for the most abundant one is reported. Mass spectra (MS) were taken on an ion-trap Finnigan MS LCQ, operating in ES (+) and ES (-) ionization mode.

LCMS were taken on a quadrupole Mass Spectrometer on a Shimadzu lcms 2010 or Agilent LC/MSD 1100 Series , operating in ES (+) and ES (-) ionization mode (GC-MS) were taken on a Shimadzu 2010 GCMS with El ion source (Column: DB-5 Carrier gas: He).

LC/MS - ES (+): analysis performed on YMC ODS (50x2.0 mm, 5Dm) (mobile phase: from 90% [water +0.1% TFA] and 10% [CH3CN+0.1% TFA] to 20% [water +0.1 % TFA] and 80% [CH3CN +0.1% TFA] in 2.5 min, finally under these conditions for 0.5min; T=50OC; flux= 1.0 mL/min; LC/MS - ES (-): analysis performed on YMC ODS (50x2.0 mm, 5Dm) (mobile phase: from 90% [water +0.1% TFA] and 10% [CH3CN+0.1% TFA] to 20% [water +0.1% TFA] and 80% [CH3CN +0.1% TFA] in 3 min, finally under these conditions for 2 min; T=50°C; flux= 1.0 mL/min; HPLC (walk -up) were taken on Shimadzu 20AB HPLC with PDA detector (column: YMC ODS 50x4.6 mm, 5 cm). Mobile phase: 90% [water +0.1% TFA] and 10% [CH3CN+0.1% TFA] to 20% [water +0.1% TFA] and 80% [CH3CN +0.1% TFA] in 6 min, finally under these conditions for 2 min; T=40°C; flux= 3.0 mL/min

T. L. C. refers to thin layer chromatography on 0.25 mm silica gel plates (60F-254 China National Medicines) and visualized with UV light.

For phase separations performed by using microfiltration

Devices: phase separation cartridge with polypropylene frit by Whatman or Alltech. SCX means: SCX-cartridges (loading 0.75mmol/g) by Varian.

Solutions were dried over anhydrous sodium sulphate. Methylene chloride and DMF were redistilled over calcium hydride and tetrahydrofuran was redistilled over sodium.

Abbreviations

SFC supercritical fluid chromatogaphy

AcOH Acetic acid

Pd/C Palladium on carbon

Et₂O diethyl ether

TLC thin layer chromatography

Cat. Catalytic

Description 1. 1-Benzyl-4-methylpiperidin-4-ol (D1) )

A stirred solution of 3M methylmagnesium bromide in ether (132ml, 396mmol) was cooled by dry ice-acetone bath to -15⁰C and a solution of 1-benzylpiperidin-4-one (3Og, 158mmol) in anhydrous tetrahydrofuran (300ml) was added dropwise at -15⁰C. The mixture was stirred for 2h, the temperature rose to room temperature and the mixture was stirred overnight. After that, the mixture was quenched with saturated ammonium chloride solution (200ml) and the mixture was evaporated to remove tetrahydrofuran. The residue was diluted with ethyl acetate (2 x 500 ml), washed with saturated aqueous sodium bicarbonate solution (500ml), water and brine, then dried over sodium sulfate and concentrated in vacuo to give the title compound (26g, 80%).

¹H NMR (CD₃OD) δ: 1.15 (3H, s), 1.49-1.68 (6H, m), 2.25-2.40 (2H, m), 2.45-2.55 (2H, m), 3.45 (2H, s), 7.15 -7.30 (5H, m).

Description 2. N-(1-Benzyl-4-methylpiperidin-4-yl)acetamide (D2)

To a solution of 1-benzyl-4-methylpiperidin-4-ol (D1 , 6g, 30mmol) in acetonitrile (2.42g, 59mmol) was added cone. H₂SO₄ (98%, 5.78g, 59mmol) over 1 h at ice-salt bath temperature, then it was stirred for six days at room temperature. The mixture was diluted with acetonitrile and neutralized with 2N sodium hydroxide solution to pH9, then extracted with dichloromethane (200 ml) and the organic layer was dried and evaporated to give the title compound (6g, 83%) as yellow solid.

¹H NMR (CD₃OD) δ: 1.32 (3H, s), 1.60 (2H, t), 1.88 (3H, s), 1.96 (2H, d), 2.16 (2H, t), 2.50 (2H, m), 3.43 (2H, s), 5.10 (1 H, s), 7.17-7.25 (5H, m).

Description 3. 1-Benzyl-4-methylpiperidin-4-amine (D3)

To N-(1-benzyl-4-methylpiperidin-4-yl)acetamide (D2, 6g, 24.4mmol) was added 37% hydrochloric acid (250 ml) and the mixture was heated at reflux for 7 days. The mixture was cooled to room temperature, diluted with water (50 ml), basified with concentrated aqueous ammonia (300ml), and extracted with dichloromethane (200ml). The combined extracts were washed with water (500ml), dried and concentrated under vacuum to give the residue, which was purified by a silica gel chromatography to afford the title compound (4.5g, 90%) as yellow oil. 1H NMR (CD₃OD) δ: 1.05 (3H, s), 1.38 (2H, m), 1.55 (2H, m), 1.75 (2H, s), 2.35 (4H, m), 3.45 (2H, s), 7.17-7.25 (5H, m).

Description 4. tert-Butyl 4-a rboxylate (D4)

To a solution of 1-benzyl-4-methylpiperidin-4-amine (D3, 4.5g, 22mmol) in MeOH (20 ml) was added AcOH (1.32g, 22mmol) and Pd(OH)₂-C (cat.) at room temperature, then a solution of di-tert-butyl dicarbonate (4.8Og, 22mmol) in methanol (20ml) was added to the mixture dropwise at room temperature. The mixture was stirred overnight under 50psi hydrogen pressure, then filtered and the methanol removed under vacuum. The residue was diluted with water (20ml) and washed with ethyl acetate (30ml). The water phase was adjusted to pH>12 with aqueous ammonia and extracted with dichloromethane (100ml). The extract was dried, filtered and concentrated to give the title compound (3.5g, 95%) as yellow oil. 1H NMR (CDCI₃) δ: 1.11 (3H, s), 1.30-1.50 (13H, m), 1.70-2.01 (2H, b), 3.35-3.38 (4H, m).

Description 5. tert-Butyl 4-methyl-4-(5-methyl-2-nitrophenylamino)piperidine-1- carboxylate (D5)

To a solution of tert-butyl 4-amino-4-methyl-1-piperidinecarboxylate (D4, 3.5g, 16 mmol) in dry N,N-dimethylformamide (30ml) was added potassium carbonate (3.46g, 25mmol) and 3-fluoro-4-nitrotoluene (3.1 1g, 20 mmol) at room temperature and the mixture subsequently stirred overnight at 1 1O⁰C. The mixture was cooled to room temperature and the mixture was diluted with ethyl acetate (300ml) and washed with water (200ml). The organic phase was dried, filtered, concentrated and purified by silica gel chromatography to give the title compound (3.5g, 61.4%) as yellow solid.

¹H NMR (CDCI₃) δ: 1.39 (9H, s), 1.46 (3H, s), 1.62 (2H, m), 2.04 (2H, d), 2.27 (3H, s), 3.11 (2H, t), 3.71 (2H, m), 6.38 (1 H, d), 6.73 (1 H, s), 8.02 (1 H, d), 8.40 (1 H, s).

Description 6. tert-Butyl 4-(2-amino-5-methylphenylamino)-4-methylpiperidine-1- carboxylate (D6)

To a mixture of Pd/C (catalytic) in methanol (50ml), tert-butyl 4-methyl-4-(5-methyl-2- nitrophenylamino)piperidine-1-carboxylate (D5, 3.5g, l Ommol) was added at room temperature. Air in the vessel was displaced with nitrogen and subsequently with hydrogen and the contents in the vessel were stirred at 4O⁰C overnight under hydrogen at 8psi. The mixture was filtered and the methanol was removed under vacuum to give the title compound (3 g, 94%).

¹H NMR (d₆-DMSO) δ: 1.12 (3H,s), 1.25-1.30 (9H, s), 1.30-1.40 (2H, m), 1.72-1.78 (2H, m), 2.01 (3H, s), 3.25-3.30 (3H, m), 3.49 (1 H, m), 4.15-4.55 (3H, b), 6.25 (1 H, d), 6.41 (2H, m).

Description 7. tert-Butyl 4-methyl-4-(6-methyl-2-oxo-2,3-dihydro-1H-benzimidazol-1 - yl)-1-piperidinecarboxylate (D7)

To a solution of tert-butyl 4-(2-amino-5-methylphenylamino)-4-methylpiperidine-1- carboxylate (D6, 3g, 9.4mmol) in tetrahydrofuran (30ml) was added carbonyl diimidazole (5.15g 23.5mmol) at room temperature, then the mixture was heated at 6O⁰C with stirring overnight. The mixture was cooled to room temperature, concentrated under vacuum and purified by silica gel chromatography to give the title compound (3.2g, 98%). 1H NMR (CDCI₃) δ: 1.39 (9H, s), 1.56 (3H, s), 1.85 (2H, m), 2.31 (3H, s), 2.93 (2H, d), 3.27 (2H, m), 3.62 (2H, m), 6.78(1 H, d), 6.88 (1 H, d), 7.01 (1 H, s), 9.84 (1 H, s).

Description 8. 6-Methyl-1 -(4-methyl-4-piperidinyl)-1 ,3-dihydro-2H-benzimidazol-2- one hydrochloride (D8)

tert-Butyl 4-methyl-4-(6-methyl-2-oxo-2,3-dihydro-1 H-benzimidazol-1-yl)-1- piperidinecarboxylate (D7, 3.2g, 9.3mmol) and 3N HCI in Et₂O (20 ml) was stirred overnight at room temperature. The mixture was concentrated to dryness under vacuum and the residue was washed with Et₂O. The residue was concentrated to dryness to give the title compound (2g, 88%) as white solid.

MH⁺ 246. 1H NMR (CD₃OD) δ: 1.63 (3H, s), 2.03 (2H, t), 2.38 (3H, s), 3.15 (2H, t), 3.38 (4H, m), 6.93

(2H, m), 7.21 (1 H, s).

Description 9. tert-Butyl 3-methyl-4-oxo-1 -piperidinecarboxylate (D9)

To a solution of tert-butyl 4-oxo-1 -piperidinecarboxylate (20 g, 0.1 mol) in anhydrous tetrahydrofuran (200 ml) was added a solution of potassium bis(trimethylsilyl)amide in toluene (260ml, 0.13mol) and stirred at room temperature. After 2h, iodomethane (8.04 ml, 0.13mol) was added and the mixture was stirred overnight at room temperature. The mixture was washed by water (100ml) and extracted with ethyl acetate (100ml). After separation, the organic layer was dried and purified by column chromatography on silica gel (30:1 petroleum ether/ethyl acetate) to give the title compound (racemic mixture) (4.8 g, 22.5 %) as yellow liquid.

¹H NMR (CDCI₃) δ: 1.05 (3H, d), 1.45 (9H, s), 2.35-2.55 (3H, m), 2.80 (1 H, m), 3.25 (1 H, m), 4.15 (2H, m).

Description 10. tert-Butyl 4-amino-3-methyl-1 -piperidinecarboxylate (D10)

To a suspension of 10% Pd-C catalyst (120 mg) in ammonia-saturated methanol (50 ml) was added tert-butyl 3-methyl-4-oxo-1-piperidinecarboxylate (D9, 1.2 g, 5.6mmol) and the mixture was stirred overnight at room temperature under 50psi hydrogen atmosphere. The mixture was filtered, the solid washed by methanol (10ml) and the filtrate was concentrated to give the title compound (mixture of isomers) (1.2 g, 100 %). This was used without further purification.

¹H NMR (CDCI₃) δ: 0.85 (3H, m), 1.38 (9H, m), 1.48-1.65 (3H, m), 1.74 (1 H, m), 2.28 (1 H, m), 2.60-4.1 1 (4H, m).

Description 11. tert-Butyl 3-methyl-4-(5-methyl-2-nitrophenylamino)piperidine-1- carboxylate (D11)

3-Fluoro-4-nitrotoluene (1.73 g, 11.18 mmol) was dissolved in dry N,N-dimethylformamide (48 ml) and diisopropylethylamine (62.4ml, 13.44mmol) and tert-butyl 4-amino-3-methyl-1- piperidinecarboxylate (D10, 2.4 g 11.8mmol) were added at room temperature. The mixture was stirred for 1 h at room temperature, then stirred at 8O⁰C overnight. The mixture was extracted with ethyl acetate (25 ml) and washed with water (25ml). After separation, the organic layer was dried (Na₂SO₄) and purified by column chromatography on silica gel (5:1 petroleum ether/ethyl acetate) to give the title compound (mixture of isomers) (2.6 g, 63.4 %).

¹H NMR (CDCI₃) δ: 0.90 (3H, m), 1.41 (9H, s), 1.69 (2H, m), 2.05 (1 H, m), 2.27 (3H, s), 2.45-2.92 (1 H, m), 3.15-3.45 (2H, m), 3.50-3.80 (1 H, m), 3.90-4.12 (1 H, m), 6.38 (1 H, t), 6.56 (1 H, d), 8.05 (1 H, dd), 8.02-8.31 (1 H, m). Description 12. tert-Butyl 4-(2-amino-5-methylphenylamino)-3-methylpiperidine-1- carboxylate (2 samples D12a and D12b)

2 samples (D12a and D12b) tert-Butyl 3-methyl-4-(5-methyl-2-nitrophenylamino)piperidine-1-carboxylate (D11 , 2.5g, 7.15mmol) was suspended in methanol (60ml) and 10% Pd-C (250 mg) was added at room temperature and the mixture was stirred under 10psi hydrogen atmosphere overnight. After filtration the mixture was concentrated to yield crude product (1.6 g, 70 %) as purple solid. This was separated by preparative TLC to give two samples of the title compound (both assumed mixture of isomers). Sample A (higher rf) D12a, 700mg

¹H NMR (CDCI₃) δ: 1.01 (3H, m), 1.25 (2H, m), 1.45 (9H, s), 2.10 (1 H, m), 2.26 (3H, s), 2.51-4.10 (5H, m), 6.45 (2H, m), 6.65 (1 H, d).

Sample B (lower rf) D12b, 900 mg

¹H NMR (CDCI₃) δ: 0.95 (3H, m), 1.45 (9H, s), 1.72 (2H, m), 2.15 (1 H, m), 2.26 (3H, m), 2.80-4.10 (5H, m), 6.51 (2H, m), 6.65 (1 H, d).

Description 13. tert-Butyl 3-methyl-4-(6-methyl-2-oxo-2,3-dihydro-1H-benzimidazol-1 -yl)-1 - piperidinecarboxylate (D13)

(D13)

To a solution of tert-butyl 4-(2-amino-5-methylphenylamino)-3-methylpiperidine-1- carboxylate - sample A (D12a, 620 mg, 1.94 mmol) in N,N-dimethylformamide (8ml) was added carbonyl diimidazole (786.8mg 4.855 mmol) in portions. The mixture was stirred for 1 h at room temperature, then heated to 100⁰C and stirred overnight. After cooling to room temperature, it was washed with water and extracted with ethyl acetate. The extract was dried (Na₂SO₄), concentrated under vacuum and the residue purified by column chromatography on silica gel (5:1 petroleum ether/ethyl acetate) to give the title compound (mixture of isomers) (450 mg, 67%).

¹H NMR (CDCI₃) δ: 0.80-1.05 (3H, m), 1.49 (9H, s), 1.70-2.02 (2H, m), 2.38 (3H, s), 2.80- 3.21 (3H, m), 3.92-4.52 (2H, m), 6.82-7.01 (3H, m), 8.42-8.61 (1 H, m).

Description 14. 6-Methyl-1 -(3-methyl-4-piperidinyl)-1,3-dihydro-2H-benzimidazol-2- one hydrochloride (D14)

To a solution of tert-butyl 3-methyl-4-(6-methyl-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl)- 1-piperidinecarboxylate (D13, 400 mg, 1.16 mmol) in methanol (2ml) was added a saturated solution of hydrogen chloride in ether (5ml) and the mixture was stirred for half an hour at room temperature. The mixture was evaporated under vacuum to give the title compound (mixture of 4 components on chiral SFC) (320 mg, 99 %) as yellow solid. This was used without purification. MH⁺ 246.

¹H NMR (CD₃OD) δ: 6.87-7.09 (3H, m), 4.45 (1 H, m), 2.85-3.71 (4H, m), 2.55 (1 H, m),

2.38 (4H, m), 2.00-2.21 (1 H, m), 0.80-1.1 1 (3H, m).

Description 15. tert-Butyl 4-amino-2-methyl-1-piperidinecarboxylate (D15)

To a suspension of Pd/C (cat.) in a solution of ammonia in MeOH (3N, 200 ml), tert-butyl

2-methyl-4-oxo-1-piperidinecarboxylate (2g, 9.4mmol) was added at room temperature.

Air in the vessel was displaced with nitrogen and subsequently with hydrogen. The contents of the vessel were stirred under hydrogen (50psi) at room temperature for two days, then filtered and the methanol was removed under vacuum to give the title compound (mixture of isomers) (800mg, 53%).

¹H NMR (CD₃OD) δ:1.25 (3H, d), 1.45 (1 1 H, m), 1.95 (1 H, m), 2.05 (1 H, m), 3.12 (1 H, m),

3.28 (1 H, m), 3.69 (1 H, m), 3.95 (1 H, m). Description 16. tert-Butyl 2-methyl-4-(5-methyl-2-nitrophenylamino)piperidine-1- carboxylate (D16)

tert-Butyl 4-amino-2-methyl-1-piperidinecarboxylate (D15, 750mg 3.5mmol) was dissolved in dry N,N-dimethylformamide (7 ml) and diisopropylethylamine (0.92ml, 5.25mmole) and

3-fluoro-4-nitrotoluene (653mg, 4.2 mmole) were added at room temperature and subsequently stirred overnight at 8O⁰C. The mixture was cooled to room temperature, diluted with ethyl acetate (100ml) and washed with water (100ml x 6). The organic phase was dried, filtered, concentrated and purified by silica gel chromatography to give the title compound (mixture of isomers) (870mg, 71 %).

¹H NMR (CDCI₃) δ: 0.92 (3H, d), 1.49 (9H, s), 1.80 (2H, m), 2.05 (2H, m), 2.35 (3H, s), 3.30 (1 H, m), 3.85-4.00 (2H, m), 4.32 (1 H, m), 6.46 (1 H, d) ,6.60 (1 H, s), 8.08 (1 H, d), 8.43 (1 H, d).

Description 17. tert-Butyl 4-(2-amino-5-methylphenylamino)-2-methylpiperidine-1- carboxylate (D17)

To a suspension of Pd/C (cat.) in methanol (18 ml), tert-butyl 2-methyl-4-(5-methyl-2- nitrophenylamino)piperidine-1-carboxylate (D16, 800mg, 2.3mmol) was added at room temperature. Air in the vessel was displaced with nitrogen and subsequently with hydrogen. The contents of the vessel were stirred overnight at 4O⁰C under hydrogen (8psi), then the mixture was filtered and the methanol was removed under vacuum to give the title compound (mixture of isomers) (700mg, 95%) as pink solid. 1H NMR (de-DMSO) 8:1.10-1.20 (3H, d), 1.30-1.40 (9H, s), 1.53-1.60 (2H, m), 1.85 (2H, m), 2.11 (3H, s), 3.0-3.50 (3H, m), 3.60 (1 H, m), 3.90 (1 H, m), 6.23 (2H, m), 6.45 (1 H, d). Description 18. tert-Butyl 2-methyl-4-(6-methyl-2-oxo-2,3-dihydro-1H-benzimidazol-

1-yl)-1-piperidinecarboxylate (

To a solution of tert-butyl 4-(2-amino-5-methylphenylamino)-2-methylpiperidine-1- carboxylate (D17, 650mg, 2.04mmol) in tetrahydrofuran (7 ml), carbonyl diimidazole (1.12g, 5.09mmol) was added at room temperature, then the mixture was heated to 6O⁰C and stirred overnight. The mixture was cooled to room temperature, concentrated under vacuum and purified by silica gel chromatography to give the title compound (mixture of isomers) (500mg, 71%). 1H NMR (CDCI₃) 8:1.20-1.30 (3H, m), 1.44 (9H, s), 1.81 (1 H, m), 2.1 1 (2H, m), 2.28 (1 H, m), 2.33 91 H, s), 3.41 (1 H, m), 3.78 (1 H, m), 3.88 (1 H, m), 4.42 (1 H, m), 6.79 (2H, m) ,6.90 (1 H, d), 8.51 (1 H, s).

Description 19. 6-Methyl-1 -(2-methyl-4-piperidinyl)-1,3-dihydro-2H-benzimidazol-2- one hydrochloride (D19)

tert-Butyl 2-methyl-4-(6-methyl-2-oxo-2,3-dihydro-1 H-benzimidazol-1-yl)-1- piperidinecarboxylate (D18, 500mg, 1.45mmol) and 3N HCI/ Et₂O (10ml) in Et₂O was stirred overnight at room temperature. The mixture was concentrated to dryness under vacuum and the residue was washed with Et₂O, then the residue was concentrated to dryness to give the title compound (mixture of isomers) (350mg, 98%, HCI salt). MH⁺ 246.

¹H NMR (CD₃OD) δ:1.30 (3H, d), 1.90 (2H, t), 2.30 (3H, s), 2.40 (1 H, q), 2.60 (1 H, m), 3.15 (1 H, m), 3.35 (1 H, m), 3.47 (1 H, dd), 4.46 (1 H, m), 6.78-6.86 (2H, m), 7.08 (1 H, s).

Example 1. 6-Methyl-1 -[4-methyl-1 -(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3- dihydro-2H-benzimidazol-2-one hydrochloride (E1)

A suspension of 6-methyl-1-(4-methyl-4-piperidinyl)-1 ,3-dihydro-2H-benzimidazol-2-one hydrochloride (D8, 50mg, 0.204mmol) in dichloroethane (2ml) at room temperature under argon was treated with triethylamine (0.2 ml) and tetrahydro-4H-pyran-4-one (286.3 mg, 2.86mmol) and the mixture was stirred overnight at 4O⁰C, then sodium triacetoxyborohydride (302mg, 1.43mmol) was added and stirred for 8h. The mixture was diluted with dichloromethane, washed with aqueous ammonia solution and the product extracted with dichloromethane. The combined organic layers were evaporated under reduced pressure and purified by preparative HPLC to afford the free base of the product, which was treated with HCI to give the title compound (10mg, 15%). MH⁺ = 330.

¹H NMR (HCI salt) (CD₃OD) δ:1.56 (3H, s), 1.68 (3H, m), 1.89-2.01 (4H, m), 2.33 (3H, s), 3.05 (2H, t), 3.31 (3H, m), 3.50-3.65 (4H, m), 3.97 (2H, dd), 6.89 (2H, m), 7.15 (1 H, s).

Example 2. 6-Methyl-1 -[3-methyl-1 -(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3- dihydro-2H-benzimidazol-2-one (E2)

To a suspension of 6-methyl-1-(3-methyl-4-piperidinyl)-1 ,3-dihydro-2H-benzimidazol-2- one hydrochloride (D14, 100 mg, 0.4 mmol) in benzene (3 ml) was added tetrahydro-4H- pyran-4-one (0.36 ml, 4 mmol) and triethylamine (0.4 ml, 2.8 mmol) and the mixture was stirred for two days under reflux at 70-80⁰C. The mixture was concentrated under vacuum and the residue was dissolved in the methanol (10 ml) and treated with catalytic 10% Pd- C (20 mg). The mixture was stirred overnight under hydrogen atmosphere at 40psi. The mixture was filtered and the filtrate was concentrated and residue purified by preparative thin layer chromatography to afford the title compound (mixture of isomers) (total yield 50mg, 38%). MH⁺ 330.

¹H NMR (CDCI₃) δ: 0.75-1.35 (3H, m), 1.55-2.65 (10H, m), 3.30-3.52 (6H, m), 4.05 (2H, m), 4.45-4.61 (1 H, m), 6.85-7.05 (3H, m). Example 3. 6-Methyl-1 -[2-methyl-1 -(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3- dihydro-2H-benzimidazol-2-one (E3)

To a suspension of 6-methyl-1-(2-methyl-4-piperidinyl)-1 ,3-dihydro-2H-benzimidazol-2- one hydrochloride (D19, 100mg, 0.408 mmol) in a mixture of acetonitrile (10ml) and N- methylpyrrolidin-2-one (10ml), tetrahydro-2H-pyran-4-yl 4-methylbenzenesulfonate (261.12mg 1.02mmol) and potassium carbonate (113 mg 0.816mmol) were added at room temperature and subsequently stirred for 2 days at 8O⁰C. The mixture was extracted with dichloromethane and the organic layer was washed with water, dried and evaporated. The residue was purified by silica gel chromatography to obtain the title compound (mixture of isomers) (40 mg, 29%). MH⁺ 330. 1H NMR (CD₃OD) δ:1.40 (3H, m), 1.65-2.21 (4H, m), 2.35-2.75 (5H, m), 3.16-3.70 (4H, m), 3.98-4.12 (2H, m), 4.45-5.25 (1 H, m), 6.99 (1 H, m), 7.30 (2H, m).

Claims

1. A compound of formula (I) or a salt thereof:

(I) wherein:

• R is C-i-βalkyl attached at the 2, 3 or 4-position of the piperidine ring;

• R⁴ is hydrogen or fluoro; • R⁵ is selected from hydrogen, halogen, cyano, C_1-6alkyl (optionally substituted with one or more fluorine atoms) and d-β alkoxy (optionally substituted with one or more fluorine atoms);

• R⁶ is selected from hydrogen, halogen, cyano, C_1-6alkyl (optionally substituted with one or more fluorine atoms), Ci_-6alkylsulfonyl, C_3-6cycloalkyl (optionally substituted with one or more fluorine atoms) and Ci_-6alkoxy (optionally substituted with one or more fluorine atoms); and

• Q is hydrogen or Ci_-6alkyl.

2. A compound as claimed in claim 1 wherein the salt is a pharmaceutically acceptable salt.

3. A compound as claimed in claim 1 or claim 2 wherein R is methyl attached at the 2, 3 or 4 position of the piperidine ring.

4. A compound as claimed in any of claims 1-3 wherein R⁴ is hydrogen.

5. A compound as claimed in any of claims 1-4 wherein R⁵ is selected from hydrogen, halogen, cyano, C_1-6alkyl (optionally substituted with one, two or three fluorine atoms) and C-i-βalkoxy (optionally substituted with one, two or three fluorine atoms).

6. A compound as claimed in any of claims 1-5 wherein R⁶ is selected from chloro, fluoro, methyl, cyclopropyl, methoxy, trifluoromethoxy and trifluoromethyl.

7. A compound as claimed in any of claims 1-6 wherein Q is hydrogen or methyl

8. A compound as claimed in claim 1 which is selected from the group consisting of: 6-methyl-1-[4-methyl-1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1 ,3-dihydro-2H- benzimidazol-2-one;

6-methyl-1-[3-methyl-1-(tetrahydro-2/-/-pyran-4-yl)-4-piperidinyl]-1 ,3-dihydro-2/-/- benzimidazol-2-one; 6-methyl-1-[2-methyl-1-(tetrahydro-2/-/-pyran-4-yl)-4-piperidinyl]-1 ,3-dihydro-2/-/- benzimidazol-2-one; and salts thereof.

9. A compound as claimed in claim 8 wherein the salt is a pharmaceutically acceptable salt.

10. A pharmaceutical composition comprising a compound as claimed in any of claims 2 to 9, and a pharmaceutically acceptable carrier thereof.

1 1. A compound as claimed in any of claim 2 to 9 for use in therapy.

12. A compound as claimed in any of claims 2 to 9 for use in the treatment of a condition wherein agonism of a muscarinic M₁ receptor would be beneficial.

13. A compound as claimed in any of claims 2 to 9 for use in the treatment of a psychotic disorder or cognitive impairment.

14. Use of a compound as claimed in any of claims 2 to 9 in the manufacture of a medicament for the treatment of a condition wherein agonism of a muscarinic M₁ receptor would be benefical.

15. Use of a compound as claimed in any one of claims 2 to 9 in the manufacture of a medicament for the treatment of a psychotic disorder or cognitive impairment.

16. A compound as claimed in any of claims 2 to 9 for the treatment of a condition wherein agonism of a muscarinic M₁ receptor would be benefical.

17. A compound as claimed in any one of claims 2 to 9 for the treatment of a psychotic disorder or cognitive impairment.

18. A method of treating a condition wherein agonism of a muscarinic M₁ receptorwould be benefical, which method comprises administering to a mammal in need thereof an effective amount of a compound as claimed in any of claims 2 to 9.

19. A method of treating a psychotic disorder or cognitive impairment, which method comprises administering to a mammal in need thereof an effective amount of a compound as claimed in any of claims 2 to 9.

20. A compound of formula (XX

wherein: R⁴ is a group R⁴ as defined in claim 1 or a group convertible to R⁴; R⁵ is a group R⁵ as defined in claim 1 or a group convertible to R⁵; R⁶ is a group R⁶ as defined in claim 1 or a group convertible to R⁶; and R' is a group R as defined in claim 1 or a group convertible to R.

21. A compound of formula (IV) or salts thereof:

wherein:

Q is as defined in claim 1 ;

R⁴ is a group R⁴ as defined in claim 1 or a group convertible to R⁴; R⁵ is a group R⁵ as defined in claim 1 or a group convertible to R⁵;

R⁶ is a group R⁶ as defined in claim 1 or a group convertible to R⁶; and R' is a group R as defined in claim 1 or a group convertible to R.

22. A compound of formula (Vl) or salts thereof:

wherein:

Q is as defined in claim 1 ;

R⁶ is a group R⁶ as defined in claim 1 or a group convertible to R⁶; R' is a group R as defined in claim 1 or a group convertible to R; and Z is a leaving group.

23. A compound of formula (X) or salts thereof:

wherein:

Q is as defined in claim 1 ;

R⁴ is a group R⁴ as defined in claim 1 or a group convertible to R⁴; R⁵ is a group R⁵ as defined in claim 1 or a group convertible to R⁵; R⁶ is a group R⁶ as defined in claim 1 or a group convertible to R⁶; and R' is a group R as defined in claim 1 or a group convertible to R.