Benzazepines with antidopaminergic activity

Abstract: Novel 2,3,4,5-tetrahydro-1H-3-benzazepines, which in the 7-position have a methoxymethyloxy group, in the 8-position hydrogen, halogen or a nitro group and in the 5-position have an optionally substituted phenyl ortho-fused ring-­ system, with interesting effects on the central nervous system.

Description: This invention relates to novel methoxymethyl ethers of 2,3,4,5-tetrahydro-1H-3-benzazepines and pharmaceutically acceptable acid addition salts thereof, to methods for their preparation, to pharmaceutical compositions containing them, and to their use for the preparation of a pharmaceutical preparation for the treatment of the central nervous system ailment of a person. In the last decade intensive pharmacological research concerning benzazepines has taken place. The pharmacological properties of benzazepines depend to a large extent on the substituents. Various substituted benzazepines exhibiting neuroleptic, anti-aggressive, anti-Parkinson and vascular effects are known. In US-A-3,393,192 derivatives of 5-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine having, inter alia , hydroxy, lower alkoxy or halogen in the 7- and/or 8-position are described. These compounds are claimed to be useful as antibacterials, antidepressants, antihypertensives and analgetics. In US-A-4,751,222 2,3,4,5-tetrahydro-1H-3-benzazepines having a heterocyclic or an ortho-fused heterocyclic ringsystem in the 5-position are described. These compounds are claimed to have antipsychotic and antidepressive effects. In GB-A-1,268,243 various 1,2,4-5-tetrahydro-3H,3-benzazepines are described as useful analgetics. In EP-A-0 331 130, state of the art in accordance with Article 54 (3) EPC, carbonic acid esters of substituted 7-hydroxy-2,3,4,5-tetrahydro-1H-3-benzazepines are described as useful in the treatment of mental disorder such as schizophrenia, other psychosis and manual-depressive disorders. DE-A-2 804 285 discloses a group of benzazepines having dopaminergic activity. More specifically, the disclosed compounds are 1-thienyl- and 1-furyl-2,3,4,5, tetrahydro-1H-3-benzazepines. From EP-A-0 200 455, 7-methoxy and 7-hydroxy substituted 2,3,4,5-tetrahydro-1H-3-benzazepines which in the 5-position have furyl, thienyl, pyridyl or ringsystems consisting of phenyl ortho-condensed with a benzene, cyclohexane, cyclohexene, cyclopentane or cyclopentene ring are known, said compounds exhibiting central and cardio-vascular effects. EP-A-0 285 919 relates to 1-substituted-2,3,4,5-tetrahydro-1H-3-benzazepines having anti-dopaminergic activity and in particular showing a selectivity for the D-1 sub-classification of dopaminergic receptors. It is the object underlying the present invention to provide novel methoxymethyl ethers of 2,3,4,5-tetrahydro-1H-3-benzazepines exhibiting useful pharmacological properties by action on the central dopaminergic system. According to the present invention this object is attained with 7-methoxymethyloxy-2,3,4,5-tetrahydro-1H-3-benzazepines having the general formula I wherein R₁ is hydrogen, halogen or nitro, R₂ and R₃ are hydrogen or C₁₋₆-alkyl, R₄ is furyl, thienyl, pyridyl or ringsystems consisting of phenyl ortho-condensed with a benzene, cyclohexane, cyclohexene, cyclopentane or cyclopentene ring in which rings one of the carbon atoms may be exchanged with oxygen, sulphur or nitrogen and pharmaceutically acceptable acid addition salts thereof. According to the present invention there is further provided a method for the preparation of a compound of formula (I) which comprises the step of reacting a compound of formula (II) wherein R₁, R₂, R₃ and R₄ are as defined in formula (I), with a compound of the formula (III) ClCH₂OCH₃. (III) Further there is provided a pharmaceutical composition containing a compound of formula (I) or a pharmaceutically acceptable acid addition salt thereof; and the use of such a compound for the preparation of a pharmaceutical composition for the treatment of the central nervous system ailment of a person. Compounds of the general formula I exhibit strong antidopaminergic effect. Thus, they potently inhibit stereotyped gnawing behaviour in mice induced by methylphenidate (i.e Acta Pharmacol. Toxicol. 31 , 1972, 488), and they also inhibit conditioned avoidance response and amphetamine cue in rats. The compounds of formula I may be presented as a mixture of optical isomers which may be resolved into the individual pure isomers. This resolution may conveniently be performed by fractional crystallization, from various solvents of the salts of compounds of the formula I with optical active acids or by other methods known from the literature, e.g. chiral column chromatography. Therefore, this invention includes all isomers, whether resolved or mixtures thereof. Particularly valuable embodiments of this invention are non-toxic, pharmaceutically acceptable acid addition salts of benzazepines of formula I. Such salts include those derived from inorganic and organic acids such as hydrochloric, hydrobromic, sulphuric, phosphoric, methanesulfonic, acetic, lactic, maleic, phthalic and tartaric acids. These salts may be prepared by methods known to professionals skilled in the art. The compounds of this invention are formulated into conventional pharmaceutical compositions according to known techniques. The dosage formulation will preferably contain the active compounds in the range of 0.5 mg to about 1000 mg for oral dosing. Typical dosage for antipsychotic effect would vary between about 0.5 to 10 mg/kg per day divided in 2 or 3 doses, administered orally. The pharmaceutical carriers employed can be conventional solid or liquid carriers. Examples of solid carriers are lactose, terra alba, sucrose, talcum, gelatin, agar, pectin, acacia, magnesium stearate and stearic acid. Examples of liquid carriers are syrup, peanut oil, olive oil and water. If a solid carrier for oral administration is used, the preparation can be tableted, placed in hard gelatin capsule in powder or pellet form or in the form of a troche or lozenge. If a liquid carrier is used, the preparation may, for example, be in the form of syrup, an emulsion, a soft gelatin capsule, a sterile injectable solution or an aqueous or non-aqueous liquid suspension. The compounds of this invention are active in a number of assays predictive for antipsychotic effect. In all models they show a strong anti-dopaminergic effect, both after intravenous and oral administration. Table 1 shows the ED₅₀ values for selected compounds in the methylphenidate induced gnawing test in mice. COMPOUND ED₅₀ (mg/kg) (+)-8-chloro-7-methoxymethyloxy-3-methyl-5-(benzofuran-7-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine 2.0 (+)-8-chloro-7-methoxymethyloxy-3-methyl-5-(2,3-dihydrobenzofuran-7-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine 5.4 The 2,3,4,5-tetrahydro-1H-3-benzazepines of the general formula I can be prepared by the following method using starting materials prepared as described in US-A-4,751,222: The compound of the invention, together with a conventional adjuvant, carrier, or diluent, and if desired in the form of a pharmaceutically-acceptable acid addition salt thereof, may be placed into the form of pharmaceutical compositions and unit dosages thereof, and in such form may be employed as solids, such as tablets or filled capsules, or liquids, such as solutions, suspensions, emulsions, elixirs, or capsules filled with the same, all for oral use, in the form of suppositories for rectal administration; or in the form of sterile injectable solutions for parenteral (including subcutaneous) use. Such pharmaceutical compositions and unit dosage forms thereof may comprise conventional ingredients in conventional proportions, with or without additional active compounds or principles, and such unit dosage forms may contain any suitable effective central nervous system ailment alleviating amount of the active ingredient commensurate with the intended daily dosage range to be employed. Tablets containing 1 mg of active ingredient or, more broadly, 1 to 30 mg, per tablet, are accordingly suitable representative unit dosage forms. The compounds of this invention can thus be used for the formulation of pharmaceutical preparations, e.g., for oral and parenteral administration to mammals including humans, in accordance with conventional methods of galenic pharmacy. Conventional excipients are such pharmaceutically acceptable organic or inorganic carrier substances suitable for parenteral or oral application which do not deleteriously react with the active compound. Examples of such carriers are water, salt solutions, alcohols, polyethylene glycols, polyhydroxyethoxylated castor oil, gelatin, lactose, amylose, magnesium stearate, talc, silicic acid, fatty acid monoglycerides and diglycerides, pentaerythritol fatty acid esters, hydroxymethylcellulose and polyvinylpyrrolidone. The pharmaceutical preparations can be sterilized and mixed, if desired, with e.g. auxilliary agents, such as lubricants, preservatives, stabilizers, wetting agents, emulsifiers, salt for influencing osmotic pressure, buffers and/or coloring substances which do not deleteriously react with the active compound. For parenteral application, particularly suitable are injectable solutions or suspensions, preferably aqueous solutions with the active compound dissolved in polyhydroxylated castor oil. Ampoules are convenient unit dosage forms. For oral application, particularly suitable are, e.g. tablets, dragees, or capsules having talc and/or a carbohydrate carrier or binder the carrier preferably being lactose and/or corn starch and/or potato starch. A syrup or elixir, for instance, can be used when a sweetened vehicle can be employed. Generally, as to broader ranges, the compounds of the invention are dispensed in unit dosage form comprising 0.05-100 mg in a pharmaceutically-acceptable carrier per unit dosage. A typical tablet, which may be prepared by conventional tabletting techniques, contains: Active compound 1.0 mg Lactosum 67.8 mg Ph.Eur. Avicel® 31.4 mg Amberlite® IRP 88 1.0 mg Magnesii stearas 0.25 mg Ph.Eur. The following examples illustrate the preparation of the novel compounds of this invention: Example 1. (+)-5-(7-benzofuranyl)-8-chloro-7-methoxymethyloxy-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine. (+)-5-(7-benzofuranyl)-8-chloro-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepin-7-ol (1.64 g, 0.005 mol) is suspended in dry ethanol (50 ml). Potassium-tert.-butylate (1.12 g, 0.010 mol) and potassiumiodide (0.10 g) are added. To the resulting solution chloromethyl methyl ether (0.84 g, 0.010 mol) is added. The reaction mixture is stirred for 3 h. The resulting suspension is filtered and the filtrate evaporated to dryness under reduced pressure. The residue is chromatographed on a silicia-gel column, using dichloromethane/methanol (25:1) as the eluent. The fractions containing the product are collected and evaporated to dryness under reduced pressure. Yield: 1.17 g (63%) light yellow oil. Microanalysis: Calc. for C₂₁H₂₂ClNO₃: C 67.8%, H 6.0%, N 3.8%. Found: C 67.5%, H 6.0%, N 3.6%. Identity: NMR 400 mHz 'H-chemical shifts in ppm. CDCl₃ as solvent, TMS as internal standard. (δ, ppm): 2.39(S,3H); 2.43 (d,lH) 2.88 (M,2H); 3.16 (M,3H); 3.30 (S,3H); 4.76 (d,lH); 4.90 (Q,2H); 6.46 (S,lH); 6.82 (d,lH); 7.06 (d,lH); 7.20 (S,lH); 7.25 (t,lH), 7.57 (d,lH) and 7.62 (d,lH) Example 2. (+)-8-chloro-5-(2,3-dihydro-benzofuran-7-yl)-7-methoxymethyloxy-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine. (+)-8-chloro-5-(2,3-dihydrobenzofuran-7-yl)-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepin-7-ol (4.95 g, 0.015 mol) and potassium-tert butylate (1.85 g, 0.016 mol) are dissolved in dry tetrahydrofuran (40 ml) at 5°C. Chloromethyl methyl ether (1.51 g, 0.019 mol) is added, the temperature raising to 35°C. The reaction mixture is stirred for 3 h, then evaporated to dryness under reduced pressure. The residue is partitioned between water and toluene after adjusting the pH to 8.0 by addition of 1 N sodiumhydroxide. The toluene phase is dried over magnesium sulphate, and evaporated to dryness under reduced pressure. The residue is crystallized from ethyl-acetate (11 ml). Yield: 3.1 g (55%) white crystals. Mp: 111 - 113°C. Microanalysis: Calc. for C₂₁H₂₄ClNO₃: C 67.5%, H 6.5%, N 3.8%. Found: C 67.5%, H 6.6%, N 3.7%. Identity : NMR 400 mHz 'H-chemical shifts in ppm. CDCl₃ as solvent, TMS as internal standard. (δ, ppm): 2.37 (broad S,4H); 2.8-3.1 (M,5H); 3.23 (t,2H); 3.40 (S,3H) 4.40 (t,lH); 4.52 (t,2H); 5.00 (S,2H); 6.57 (S,lH); 6.83 (M,2H) and 7.14 (M,2H) Example 3 (+)-5-(2,3-dihydrobenzofuran-7-yl)-7-methoxymethyloxy-3-methyl-8-nitro-2,3,4,5-tetrahydro-1H-3-benzazepine. (+)-5-(2,3-dihydrobenzofuran-7-yl)-3-methyl-8-nitro-2,3,4,5-tetrahydro-1H-3-benzazepin-7-ol (68.0 mg, 2.0 mmol) and potassium-tert-butylate (24.0 mg, 2.2 mmol) are dissolved in dry tetrahydrofuran (10 ml) at 23°C. Chloromethyl methyl ether (20.0 mg, 2.5 mmol) is added. The reaction mixture is stirred for 22 h, filtered and the filtrate evaporated to dryness under reduced pressure. The resulting light yellow oil is purified using reverse phase HPLC (column 16 mm x 250 mm, C₁₈ 7µ; eluent acetonitril/0.1M ammoniumsulphate pH 3.3 (30:70), isocratic). The fractions containing the product are pooled. The pH is adjusted to 9.0, and the product extracted into dichloromethane. The organic phase is evaporated to dryness under reduced pressure. Yield: 30 mg (39%), light yellow oil. Example 4 (+)-5-(2,3-dihydrobenzofuran-7-yl)-8-iodo-7-methoxymethyloxy-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine. (+)-5-(2,3-dihydrobenzofuran-7-yl)-8-iodo-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepin-7-ol (126.0 mg, 3.0 mmol) and potassiumm-tert-butylate 37.0 mg, 3.3 mmol) are dissolved in dry tetrahydrofuran (10 ml) at 20°C. Chloromethyl methyl ether (30.0 mg, 3.8 mmol) is added. The reaction mixture is stirred for 3.5 h, then poured into 5% sodiumhydrogencarbonate (20 ml). The product is extracted into dichloromethane (2 x 15 ml). The organic phase is evaporated to dryness under reduced pressure. Yield: 100 mg (71%), yellow oil. The product is purified by reverse phase HPLC as described in Example 3. Example 5 8-chloro-7-methoxymethyloxy-3-methyl-5-(1,2,3,4-tetrahydronapth-6-yl)-2,3,4,5-tetrahydro-1-H-3-benzazepine. 8-chloro-3-methyl-5-(1,2,3,4-tetrahydronapth-6-yl)-2,3,4,5-tetrahydro-1H-3-benzazepin-7-ol (103.0 mg, 3.0 mmol) and potassium-tert-butylate (37.0 mg, 3.3 mmol) are dissolved in dry tetrahydrofuran (10 ml) at 20°C. Chloromethyl methyl ether (30.0 mg, 3.8 mmol) is added. The reaction mixture is stirred for two days, then poured into 5% sodiumhydrogencarbonate (20 ml). The product is extracted into dicloromethane (2 x 15 ml), and the organic phase is evaporated to dryness under reduced pressure. Yield: 95 mg (82%) light yellow oil. The product is purified by reverse phase HPLC as described in Example 3.

Claims: Claims for the following Contracting States : AT, BE, CH, DE, DK, FR, GB, IT, LI, LU, NL, SE 7-methoxymethyloxy-2,3,4,5-tetrahydro-1H-3-benzazepines having the general formula (I) wherein R₁ is hydrogen, halogen or nitro, R₂ and R₃ is hydrogen or C₁₋₆-alkyl, R₄ is furyl, thienyl, pyridyl or ringsystems consisting of phenyl ortho-condensed with a benzene, cyclohexane, cyclohexene, cyclopentane or cyclopentene ring in which rings one of the carbon atoms may be exchanged with oxygen, sulphur or nitrogen, and pharmaceutically acceptable acid addition salts thereof. Compounds according to claim 1 wherein R₃ is hydrogen. Compounds according to claim 1 wherein R₁ is halogen or nitro. A compound of claim 1 which is: (+)-8-chloro-7-methoxymethyloxy-3-methyl-5-(benzofuran-7-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine or (+)-8-chloro-7-methoxymethyloxy-3-methyl-5-(2,3-dihydrobenzofuran-7-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine. A method for the preparation of a compound of formula (I) of claim 1 which comprises the step of reacting a compound of formula (II) wherein R₁, R₂, R₃ and R₄ are as defined in formula (I), with a compound of the formula (III) ClCH₂OCH₃. (III) A pharmaceutical composition containing a compound of claim 1 or a pharmaceutically acceptable acid addition salt thereof. Use of the compound of any claims 1 to 4 for the preparation of a pharmaceutical composition for the treatment of the central nervous system ailment of a person. Claims for the following Contracting State : ES A method for the preparation of 7-methoxymethyloxy-2,3,4, 5-tetrahydro-1H-3-benzazepineshaving the general formula (I) wherein R₁ is hydrogen, halogen or nitro, R₂ and R₃ is hydrogen or C₁₋₆-alkyl, R₄ is furyl, thienyl, pyridyl or ringsystems consisting of phenyl ortho-condensed with a benzene, cyclohexane, cyclohexene cyclopentane or cyclopentene ring in which rings one of the carbon atoms may be exchanged with oxygen, sulphur or nitrogen, and pharmaceutically acceptable acid addition salts thereof, which comprises the step of reacting a compound of formula (II) wherein R₁, R₂, R₃ and R₄ are as defined in formula (I), with a compound of the formula (III) ClCH₂OCH₃. (III) The method according to claim 1 wherein R₃ is hydrogen. The method according to claim 1 wherein R₁ is halogen or nitro. The method of claim 1 wherein the compound of formula (I) is: (+)-8-chloro-7-methoxymethyloxy-3-methyl-5-(benzofuran-7-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine or (+)-8-chloro-7-methoxymethyloxy-3-methyl-5-(2,3-dihydrobenzofuran-7-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine. A process for preparing a pharmaceutical composition containing a compound prepared according to the method claim 1 or a pharmaceutically acceptable acid addition salt thereof which comprises the step of mixing the compound of claim 1 or the pharamceutically acceptable acid addition salt thereof with a conventional adjuvant, carrier or diluent. Use of a compound prepared according to the method of any claims 1 to 4 for the preparation of a pharmaceutical composition for the treatment of the central nervous system ailment of a person. Claims for the following Contracting State : GR 7-methoxymethyloxy-2,3,4,5-tetrahydro-1H-3-benzazepines having the general formula (I) wherein R₁ is hydrogen, halogen or nitro, R₂ and R₃ is hydrogen or C₁₋₆-alkyl, R₄ is furyl, thienyl, pyridyl or ringsystems consisting of phenyl ortho-condensed with a benzene, cyclohexane, cyclohexene, cyclopentane or cyclopentene ring in which rings one of the carbon atoms may be exchanged with oxygen, sulphur or nitrogen, and pharmaceutically acceptable acid addition salts thereof. Compounds according to claim 1 wherein R₃ is hydrogen. Compounds according to claim 1 wherein R₁ is halogen or nitro. A compound of claim 1 which is: (+)-8-chloro-7-methoxymethyloxy-3-methyl-5-(benzofuran-7-yl)-2,3,4,5-tetrahydro-1H-3 benzazepine or (+)-8-chloro-7-methoxymethyloxy-3-methyl-5-(2,3-dihydrobenzofuran-7-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine. A method for the preparation of a compound of formula (I) of claim 1 which comprises the step of reacting a compound of formula (II) wherein R₁, R₂, R₃ and R₄ are as defined in formula (I), with a compound of the formula (III) ClCH₂OCH₃. (III) A process for preparing a pharmaceutical composition containing a compound of claim 1 or a pharmaceutically acceptable acid addition salt thereof which comprises the step of mixing the compound of claim 1 or the pharmaceutically acceptable acid addition salt thereof with a conventional adjuvant, carrier or diluent. Use of the compound of any claims 1 to 4 for the preparation of a pharmaceutical composition for the treatment of the central nervous system ailment of a person.

Inventors: HANSEN KRISTIAN TAGE, HANSEN LOUIS BRAMMER, HANSEN, KRISTIAN TAGE, HANSEN, LOUIS BRAMMER
Applicants: NOVONORDISK AS, NOVO NORDISK A/S
Application year: 1990
Main classification: C07D233
IPC codes: C07D403, A61K31, C07D409, A61P25, C07D405, C07D223, C07D401