Triazole compounds with dopamine-D3-receptor affinity

The invention relates to triazole compounds and to the use of these compounds. These compounds possess valuable therapeutic properties and can be used for treating diseases which respond to the influence of dopamine D 3 receptor ligands.

Compounds of the type which is under discussion here and which possess physiological activity are already known. Thus, WO 94/25013; 96/02520; 97/43262; 97/47602; 98/06699; 98/49145; 98/50363; 98/50364 and 98/51671 describe compounds which act on the dopamine receptors. DE 44 25 144 A, WO 96/30333, WO 97/25324, WO 97/40015, WO 97/47602, WO 97/17326, EP 887 350, EP 779 284 A and Bioorg. & Med. Chem. Letters 9 (1999) 2059-2064 disclose further compounds which possess activity as dopamine D 3 receptor ligands. U.S. Pat. Nos. 4,338,453; 4,408,049 and 4,577,020 disclose triazole compounds which possess antiallergic or antipsychotic activity. WO 93/08799 and WO 94/25013 describe compounds of the type which is under discussion here and which constitute endothelin receptor antagonists. Additional triazole compounds, which inhibit blood platelet aggregation and which have a hypotensive effect are described in Pharmazie 46 (1991), 109-112. Further triazole compounds which possess physiological activity are disclosed in EP 691 342, EP 556 119, WO 97/10210, WO 98/24791, WO 96/31512 and WO 92/20655.

Neurons obtain their information by way of G protein-coupled receptors, inter alia. There are a large number of substances which exert their effect by way of these receptors. One of them is dopamine.

A number of facts about the presence of dopamine, and its physiological function as a neurotransmitter, are known with certainty. Disturbances of the dopaminergic transmitter system result in diseases such as schizophrenia, depression and Parkinson's disease. These, and other, diseases are treated with drugs which interact with the dopamine receptors.

By 1990, two subtypes of dopamine receptor had been clearly defined pharmacologically, namely the D 1 and D 2 receptors.

More recently, a third subtype has been found, namely the D 3 receptor, which appears to mediate some of the effects of the antipsychotic and anti-Parkinson agents (J. C. Schwartz et al., The Dopamine D 3 Receptor as a Target for Antipsychotics, in Novel Antipsychotic Drugs, H. Y. Meltzer, Ed. Raven Press, New York 1992, pages 135-144; M. Dooley et al., Drugs and Aging 1998, 12, 495-514).

Since D 3 receptors are chiefly expressed in the limbic system, it is assumed that while a selective D 3 ligand would probably have the properties of known antipsychotic agents, it would not have their dopamine D 3 receptor-mediated neurological side-effects (P. Sokoloff et al., Localization and Function of the D 3 Dopamine Receptor, Arzneim. Forsch./Drug Res . 42(1), 224 (1992); P. Sokoloff et al. Molecular Cloning and Characterization of a Novel Dopamine Receptor (D 3 ) as a Target for Neuroleptics, Nature , 347, 146 (1990)).

Surprisingly, it has now been found that certain triazole compounds exhibit a high affinity for the dopamine D 3 receptor and a low affinity for the D 2 receptor. These compounds are consequently selective D 3 ligands.

The present invention relates, therefore, to the compounds of the formula I:

where

R 1 is H, C 1 -C 6 -alkyl, which may be substituted by OH, OC 1 -C 6 -alkyl, halogen or phenyl, C 3 -C 6 -cycloalkyl or phenyl;

R 2 is H, C 1 -C 6 -alkyl, which may be substituted by OH, OC 1 -C 6 -alkyl, halogen or phenyl, C 1 -C 6 -alkoxy, C 1 -C 6 -alkylthio, C 2 -C 6 -alkenyl, C 2 -C 6 -alkynyl, C 3 -C 6 -cycloalkyl, halogen, CN, COOR 3 , CONR 3 R 4 , NR 3 R 4 , SO 2 R 3 , SO 2 NR 3 R 4 , or an aromatic radical which is selected from phenyl, naphthyl and a 5- or 6-membered heterocyclic radical having 1, 2, 3 or 4 heteroatoms which are selected, independently of each other, from O, N and S, with it being possible for the aromatic radical to have one or two substituents which are selected, independently of each other, from C 1 -C 6 -alkyl, which may be substituted by OH, OC 1 -C 6 -alkyl, halogen or phenyl, C 1 -C 6 -alkoxy, C 2 -C 6 -alkenyl, C 2 -C 6 -alkynyl, C 3 -C 6 -cycloalkyl, halogen, CN, COR 3 , NR 3 R 4 , NO 2 , SO 2 R 3 , SO 2 NR 3 R 4 and phenyl which may be substituted by one or two radicals which are selected, independently of each other, from C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, NR 3 R 4 , CN, CF 3 , CHF 2 or halogen;

R 3 and R 4 are, independently of each other, H, C 1 -C 6 -alkyl, which may be substituted by OH, OC 2 -C 6 -alkyl, halogen or phenyl, or phenyl;

A is C 4 -C 10 -alkylene or C 3 -C 10 -alkylene which comprises at least one group Z which is selected from O, S, CONR 3 , COO, CO, C 3 -C 6 -cycloalkyl and a double or triple bond;

B is a radical of the following formulae (a) and (b):

X is CH 2 or CH 2 CH 2 ;

Y is CH 2 or O;

R 6 and R 7 are, independently of each other, selected from H, C 1 -C 6 -alkyl, which may be substituted by halogen, OH, C 1 -C 6 -alkoxy, C 2 -C 6 -alkenyl, halogen, CN, NO 2 , SO 2 R 3 , SO 2 NR 3 R 4 , CONR 3 R 4 , NHSO 2 R 3 and NR 3 R 4 ;

and the salts thereof with physiologically tolerated acids.

The compounds according to the invention are selective dopamine D 3 receptor ligands which act in the limbic system in a regioselective manner and which, as a result of their low affinity for the D 2 receptor, have fewer side-effects than do the classic neuroleptic agents, which are D 2 receptor antagonists. The compounds can therefore be used for treating diseases which respond to dopamine D 3 ligands, i.e. they are effective for treating those diseases in which affecting (modulating) the dopamine D 3 receptors leads to an improvement in the clinical picture or to the disease being cured. Examples of such diseases are diseases of the cardiovascular system and the kidneys, diseases of the central nervous system, in particular schizophrenia, affective disorders, neurotic stress and somatoform disorders, psychoses, parkinsonism, attention deficit disorders, hyperactivity in children, epilepsy, amnesic and cognitive disorders such as learning and memory impairment (impaired cognitive function), anxiety states, dementia, delirium, personality disorders, sleep disturbances (e.g. restless legs syndrome), disorders of sex life (male impotence), eating disorders and addictive disorders. Moreover they are useful in the treatment of stroke.

Addictive disorders include the psychological disorders and behavioral disturbances caused by abuse of psychotropic substances such as pharmaceuticals or drugs, and other addictive disorders such as compulsive gambling (impulse control disorders not elsewhere classified). Addictive substances are, for example: opioids (e.g. morphine, heroin, codeine); cocaine; nicotine; alcohol; substances which interact with the GABA chloride channel complex, sedatives, hypnotics or tranquilizers, e.g. benzodiazepines; LSD; cannabinoids; psychomotor stimulants such as 3,4-methylenedioxy-N-methylamphetamine (ecstasy); amphetamine and amphetamine-like substances such as methylphenidate or other stimulants including caffeine. Addictive substances of particular concern are opioids, cocaine, amphetamine or amphetamine-like substances, nicotine and alcohol.

The compounds according to the invention are preferably employed for treating affective disorders; neurotic, stress and somatoform disorders and psychoses, e.g. schizophrenia.

Within the context of the present invention, the following expressions have the meanings given in conjunction with them:

Alkyl (also in radicals such as alkoxy, alkylthio, alkylamino etc.) is a straight-chain or branched alkyl group having from 1 to 6 carbon atoms and, in particular from 1 to 4 carbon atoms. The alkyl group can have one or more substituents which are selected, independently of each other, from OH, OC 1 -C 6 -alkyl, halogen or phenyl. In the case of a halogen substituent, the alkyl group can, in particular, encompass, 1, 2, 3 or 4 halogen atoms which can be located on one or more C atoms, preferably in the α or ω position. CF 3 , CHF 2 , CF 2 Cl or CH 2 F are particularly preferred.

Examples of an alkyl group are methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, t-butyl, etc.

Cycloalkyl is, in particular, C 3 -C 6 -cycloalkyl, such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

Alkylene radicals are straight-chain or branched. If A does not have a group Z, A then comprises from 4 to 10 carbon atoms, preferably from 4 to 8 carbon atoms. The chain between the triazole nucleus and group B then has at least four carbon atoms. If A has at least one of said Z groups, A then comprises from 3 to 10 carbon atoms, preferably from 3 to 8 carbon atoms.

If the alkylene groups comprise at least one of the Z groups, this or these groups can then be arranged in the alkylene chain at an arbitrary site or in position 1 or 2 of the A group (seen from the triazole radical). The radicals CONR 2 and COO are preferably arranged such that the carbonyl group is in each case facing the triazole ring. Particular preference is given to the compounds of the formula I in which A is —Z—C 3 -C 6 -alkylene, in particular —Z—CH 2 CH 2 CH 2 —, —Z—CH 2 CH 2 CH 2 CH 2 —, —Z—CH 2 CH═CHCH 2 —, —Z—CH 2 C(CH 3 )═CHCH 2 —,

—Z—CH 2 CH(CH 3 )CH 2 —or a linear —Z—C 7 -C 10 -alkylene radical, with Z being bonded to the triazole ring. Z is preferably CH 2 , O and in particular S. Preference is additionally given to A being —(CH 2 ) 4 —, —(CH 2 ) 5 —, —CH 2 CH 2 CH═CHCH 2 —,

—CH 2 CH 2 C(CH 3 )═CHCH 2 — or —CH 2 CH 2 CH(CH 3 )CH 2 —.

Halogen is F, Cl, Br or I, preferably F or Cl.

R 1 is preferably H, C 1 -C 6 -alkyl or C 3 -C 6 -cycloalkyl.

If R 2 is an aromatic radical, this radical is then preferably one of the following radicals:

where

R 9 to R 11 are H or the abovementioned substituents of the aromatic radical,

R 12 is H, C 1 -C 6 -alkyl or phenyl, and

T is N or CH.

If the phenyl radical is substituted, the substituents are preferably in the m position or the p position.

The aromatic radical is particularly preferably a group of the formula:

where R 9 , R 10 and R 12 have the abovementioned meanings. The indicated phenyl, pyridyl, thiazolyl and pyrrole radicals are particularly preferred.

The radicals R 9 to R 11 are preferably H, C 1 -C 6 alkyl, OR 3 , CN, phenyl, which may be substituted by C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy or halogen, CF 3 and halogen, and are, in particular, H, C 1 -C 6 -alkyl, OR 3 and halogen. In this context, R 3 has the abovementioned meanings.

Particularly preferably, R 2 is H, C 1 -C 6 -alkyl, NR 3 R 4 (R 3 and R 4 are, independently of each other, H or C 1 -C 6 -alkyl), phenyl or a 5-membered aromatic heterocyclic radical which has 1 or 2 heteroatoms which are independently selected from N, S and O. The heterocyclic radical is preferably a pyrrole radical or a pyridine radical.

X and/or Y are preferably CH 2 .

A is preferably C 4 -C 10 -alkylene or C 3 -C 10 -alkylene which comprises at least one group Z which is selected from O, S, COO, CO and a double bond.

Preferably, at least one of the radicals R 6 , R 7 and R 8 is H.

The radicals R 6 and R 7 are preferably, and independently of each other, selected from H, C 1 -C 6 -alkyl, OH, C 1 -C 6 -alkoxy, C 1 -C 6 -alkylthio-C 1 -C 6 -alkyl, halogen, CN, NO 2 , SO 2 R 3 , SO 2 NR 3 R 4 and CONR 3 R 4 . Particularly preferably, the phenyl group has one or two substituents, i.e. one or two of the radicals R 6 and R 7 is/are C 1 -C 6 -alkyl, OH, halogen, CN, SO 2 NR 3 R 4 1 NO 2 or CF 3 .

Particular preference is given to the compounds of formula I where

R 1 is H, C 1 -C 6 -alkyl or phenyl,

R 2 is H, C 1 -C 6 -alkyl, phenyl, thienyl, furanyl, pyridyl, pyrrolyl, thiazolyl or pyrazinyl,

A is —SC 3 -C 10 -alkylene which can comprise a double bond, and

R 6 and R 7 are selected from H, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, halogen, SO 2 NR 3 R 4 ; CN, NO 2 and CF 3 .

The invention also encompasses the acid addition salts of the compounds of the formula I with physiologically tolerated acids. Examples of suitable physiologically tolerated organic and inorganic acids are hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, oxalic acid, maleic acid, fumaric acid, lactic acid, tartaric acid, adipic acid or benzoic acid. Other acids which can be used are described in Fortschritte der Arzneimittelforschung [Advances in pharmaceutical research], Volume 10, pages 224 ff., Birkhäuser Verlag, Basle and Stuttgart, 1966.

The compounds of the formula I can exhibit one or more centers of asymmetry. The invention therefore includes not only the racemates but also the relevant enantiomers and diastereomers.

The respective tautomeric forms are also included in the invention.

The process for preparing the compounds of the formula I consist in

a) reacting a compound of the formula (II)

where Y 1 is a customary leaving group, such as Hal, alkylsulfonyloxy, arylsulfonyloxy, etc., with a compound of the formula (III)

HB  (III);

or

b) reacting a compound of the formula (IV)

where Z 1 is O or S, and A 1 is C 1 -C 10 -alkylene or a bond, with a compound of the formula (V),

Y 1 —A 2 —B  (V)

where Y 1 has the abovementioned meaning and A 2 is C 2 -C 10 -alkylene, with A 1 and A 2 together having from 3 to 10 C atoms and A 1 and/or A 2 where appropriate comprising at least one group Z; or

c) reacting a compound of the formula (VI)

where Y 1 and A 1 have the abovementioned meanings, with a compound of the formula (VII)

H—Z 1 —A—B  (VII)

where Z 1 has the abovementioned meanings; or

d) reversing the polarity of a compound of the formula (VIII)

using reagents which are known from the literature, such as 1,3-propanedithiol, KCN/water, TMSCN (trimethylsilyl cyanide) or KCN/morpholine, as described, for example, in

Albright Tetrahedron , 1983, 39, 3207 or

D. Seebach Synthesis 1969, 17 und 1979, 19 or

H. Stetter Angew. Chem. Int. Ed . 1976, 15, 639 or

van Niel et al. Tetrahedron 1989, 45, 7643

Martin et al. Synthesis 1979, 633,

to give the products (VIIIa) (using 1,3-propanedithiol by way of example)

and then chain-elongating with compounds of the formula (IX)

Y 1 —A 3 —B  (IX)

where Y 1 has the abovementioned meaning and A 3 is C 3 -C 9 -alkylene which can contain a group Z,

with compounds of the formula (Ia)

where Z 2 is CO or a methylene group, and Z 2 and A 2 have together from 4 to 10 C atoms, being obtained after deprotecting or reducing, or

e) reacting a compound of the formula (VIII) with a compound of the formula (X)

Y 2 —A—B  (X)

where Y 2 is a phosphorane or a phosphonic ester, in analogy with customary methods, as described, for example, in Houben Weyl “ Handbuch der Organischen Chemie ” [Textbook of Organic Chemistry], 4th Edition, Thieme Verlag Stuttgart, Volume V/lb p. 383 ff, or Vol. V/1c p. 575 ff, or

f) reacting a compound of the formula (XI)

where Q is H or OH, with a compound of the formula III under reductive conditions in analogy with methods known from the literature, for example as described in J. Org. Chem . 1986, 50, 1927; or WO 92/20655.

The process for preparing a compound of the formula I where A comprises the groups COO or CONR 3 consists in reacting a compound of the formula (XII)

where Y 3 is OH, OC 1 -C 4 -alkyl, Cl or, together with CO, an activated carboxyl group, and A 4 is C 0 -C 9 -alkylene, with a compound of the formula (XIII)

B—A—Z 3   (XIII)

where Z 3 is OH or NHR 3 .

Compounds of the type (XIV)

can be synthesized by alkylating compounds of the formula (IV) with compounds of the formula (XV),

to give compounds of the formula (XVI),

subsequently carrying out hydrazinolysis to give compounds of the type (XVII)

Compounds of the formula XVII (or XIV) can also be obtained by reacting compounds of the formula II with azides, such as sodium azide, and then reducing, as described, for example, in H. Staudinger, Helv. Chim. Acta 1985, 2, 635 or R. Carrie, Bull. Chem. Soc. Fr. 1985, 815.

Compounds of the general formulae B-H can be prepared as described, for example, in

S. Smith et al., Bioorg. Med. Chem. Lett . 1998, 8, 2859;

WO 97/47602, WO 920655 and W098/24791, or

J. Med. Chem . 1987, 30, 2111 and 2208.

The compounds of the formula (IV) type are either known or can be prepared using known methods, as described, for example, in A. R. Katritzky, C. W. Rees (ed.) “Comprehensive Heterocyclic Chemistry”, Pergamon Press, or “The Chemistry of Heterocyclic Compounds” J. Wiley & Sons Inc. N.Y. and the literature which is cited therein, or in S. Kubota et al. Chem. Pharm. Bull . 1975, 23, 955 or Vosilevskii et al. Izv. Akad. Nauk. SSSR Ser. Khim. 1975, 23, 955.

In the above formulae, R 1 , R 2 , R 6 , R 7 , A, B, X and Y have the meanings given in connection with formula I.

The compounds according to the invention, and the starting materials and the intermediates, can also be prepared in analogy with the methods which are described in the patent publications which were mentioned at the outset.

The above-described reactions are generally effected in a solvent at temperatures of between room temperature and the boiling temperature of the solvent employed. Examples of solvents which can be used are esters, such as ethyl acetate, ethers, such as diethyl ether or tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, dimethoxyethane, toluene, xylene, acetonitrile, ketones, such as acetone or methyl ethyl ketone, or alcohols, such as ethanol or butanol.

If desired, the reactions can be carried out in the presence of an acid-binding agent. Suitable acid-binding agents are inorganic bases, such as sodium carbonate or potassium carbonate, or sodium hydrogencarbonate or potassium hydrogencarbonate, sodium methoxide, sodium ethoxide, sodium hydride, or organometallic compounds, such as butyl lithium or alkyl magnesium compounds, or organic bases, such as triethylamine or pyridine. The latter can also simultaneously serve as the solvent.

Process (f) is effected under reducing conditions, e.g. using sodium borohydride, sodium cyanoborohydride or triacetoxy borohydride, where appropriate in an acid medium or in the presence of a Lewis acid, such as zinc chloride, or by way of catalytic hydrogenation.

The crude product is isolated in a customary manner, for example by means of filtering, distilling off the solvent or extracting from the reaction mixture, etc. The resulting compounds can be purified in a customary manner, for example by recrystallization from a solvent, by chromatography or by converting into an acid addition compound.

The acid addition salts are prepared in a customary manner by mixing the free base with the corresponding acid, where appropriate in solution in an organic solvent, for example a lower alcohol, such as methanol, ethanol or propanol, an ether, such as methyl tert-butyl ether, a ketone, such as acetone or methyl ethyl ketone, or an ester, such as ethyl acetate.

For treating the abovementioned diseases, the compounds according to the invention are administered orally or parenterally (subcutaneously, intravenously, intramuscularly or intraperitoneally) in a customary manner. The administration can also be effected through the nasopharyngeal space using vapors or sprays.

The dosage depends on the age, condition and weight of the patient and on the type of administration. As a rule, the daily dose of active compound is from about 10 to 1000 mg per patient and day when administered orally and from about 1 to above 500 mg per patient and day when administered parenterally.

The invention also relates to pharmaceuticals which comprise the compounds according to the invention. In the customary pharmacological administration forms, these pharmaceuticals are present in solid or liquid form, for example as tablets, film tablets, capsules, powders, granules, sugar-coated tablets, suppositories, solutions or sprays. In this context, the active compounds can be worked up together with the customary pharmacological auxiliary substances, such as tablet binders, fillers, preservatives, tablet disintegrants, flow-regulating agents, plasticizers, wetting agents, dispersants, emulsifiers, solvents, retarding agents, antioxidants and/or propellent gases (cf. H. Sucker et al., Pharmazeutische Technologie, Thieme-Verlag, Stuttgart, 1978). The resulting administration forms normally comprise the active compound in a quantity of from 1 to 99% by weight.

The following examples serve to explain the invention without limiting it.