IMIDAZOLE DERIVATIVES, PROCESSES FOR THE PREPARATION OF THE SAME, PHARMACEUTICAL COMPOSITIONS COMPRISING THE SAME, THE USE OF THE SAME FOR THE MANUFACTURE OF MEDICAMENTS OF THERAPEUTIC VALUE, AND INTERMEDIATES FORMED DURING SAID PROCESSES

Abstract: Novel imidazole of the formula: wherein Ring A is pyridyl group or a substituted pyridyl group; Ring B is phenyl group or a substituted phenyl group; R¹ and R² are hydrogen atom or are combined together to form a group of the formula: -(CH₂) q -; m is 1 or 2; n is 0, 1 or 2; and q is 3 or 4, or a salt thereof are disclosed. Said derivative (I) and a salt thereof are useful an anti-ulcer agents. Processes for the preparation of such derivatives are also provided, together with chemical intermediates formed during said processes. Pharmaceutical composi­ tions comprising the same are further provided. The use of such compounds is also provided for the manufacture of medicaments of therapeutic value.

Description: This invention relates to a novel imidazole derivative and processes for preparing same. More particularly, it relates to an imidazole derivative of the formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹ and R² are hydrogen atoms or are combined together to form a group of the formula: -(CH₂) q -; m is 1; n is 0 or 1; and q is 3 or 4, or a pharmaceutically acceptable acid addition salt thereof. Excessive gastric acid secretion is one of causative factors of peptic ulcer diseases such as gastric ulcer and duodenal ulcer. Since the acid secretion by gastric parietal cells is known to be induced by histamine, acetylcholine or gastrin, cholinergic receptor blockers (e.g., atropine) and histamine H₂-receptor blockers (e.g., cimetidine) which antagonize these stimuli in living tissues have been used for treatment of such ulcer diseases [Medicina, 23 (4) 560-565 (1986)]. Moreover, benzimidazole compounds such as omeprazole have been recently found to show the antisecretory effects due to their inhibitory effect on the enzymatic activity of H⁺/K⁺ ATPase (i.e., the enzyme which plays an important role in concentration and/or secretion of gastric acid ) (Japanese Patent Publication (unexamined) No. 141783/1979). However, among these known drugs, cholinergic receptor blockers are still unsatisfactory for clinical use because of strong toxicity (e.g., atropine toxicosis). Cimetidine, one of the histamine H₂ receptor blockers, is also known to have unfavorable side effects such as anti-androgen effect and prolactin release-stimulating effect. EP-A-0125756 and EP-A-0174717 describe various substituted sulfinyl-benzimidazole derivatives which are useful as anti-ulcer agents. In particular, these references respectively disclose the use of 2-(2-pyridylmethyl)-1-phenyl-1H-benzimidazole and 2-(2-dimethylaminobenzylsulfinyl)-1H-benzimidazole for treating ulcers. As a result of various investigations, we have now found that the compound (I) of the present invention and a salt thereof show potent inhibitory effect against gastric acid secretion and is useful for therapeutic treatment or prophylaxis of peptic ulcer diseases. For example, when the effect of a test compound on gastrin-induced gastric acid secretion was examined by oral administration to rats, each one of 1-(2-pyridyl)-2-[2-(1-pyrrolyl)benzylsulfinyl]imidazole, 1-(3-methyl-2-pyridyl)-2-[2-(dimethylamino)benzylsulfinyl]imidazole and 1,4,5,6-tetrahydro-1-(2-pyridyl)-2-[2-(diethylamino)- benzylsulfinyl]cyclopenta[d]imidazole at the dose of 30 mg/kg showed more than 70 % decrease in gastric acid secretion as compared with non-administered group of rats. On the other hand, when the effect of a test compound on the enzyme activity of H⁺/K⁺ ATPase prepared from the porcine gastric mucosa was examined, IC₅₀ (i.e., the concentration required to induce 50% inhibition of said enzymatic activity) of 1,4,5,6-tetrahydro-1-(2-pyridyl)-2-[2-(diethylamino)benzylsulfinyl]cyclopenta[d]imidazole was about 10 µM and IC₅₀ of 1-(2-pyridyl)-2-[2-(cyclohexylamino)benzylsulfinyl]imidazole and 1-(4-methoxy-6-methyl-2-pyridyl)-2-[2-(diethylamino)benzylsulfinyl]imidazole were less than 10 µM. Examples of the compound of the present invention are those of the formula (I) in which Ring A is a 2- or 4-pyridyl group which may optionally have a substituent selected from a lower alkyl group such as methyl group or ethyl group or a lower alkoxy group such as methoxy group, ethoxy group or isopropoxy group. Ring B is a phenyl group having one substituent selected from amino group, a mono- or di(lower alkyl)amino group such as methylamino group, ethylamino group, dimethylamino group, diethylamino group or dipropylamino group, or a morpholino group. pyrrolidinyl group or piperidino group; R¹ and R² are hydrogen atom or are combined together to form trimethylene group or tetramethylene group; m is 1; and n is 0 or 1. Among them, preferred examples of the compound of the invention are those of the formula (I) in which Ring A is 2- or 4- pyridyl group which may optionally have one or two substituent(s) selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is phenyl group one substituent selected from a di(C₁₋₄ alkyl)amino group and a morpholino group; R¹ and R² are hydrogen atom or are combined together to form trimethylene group; m is 1; and n is 0 or 1. More preferred examples of the compound of the invention are those of the formula (I) in which Ring A is 2- or 4-pyridyl group, a 3-, 4- or 5-(C₁₋₄ alkoxy)-2-pyridyl group or a 3-, 4-, 5- or 6-(C₁₋₄ alkyl)-2-pyridyl group; Ring B is a 2-morpholinophenyl group or a 2-di(C₁₋₄ alkyl)aminophenyl group; R¹ and R² are hydrogen atom or are combined together to form trimethylene group; m is 1; and n is 0 or 1. Most preferred examples of the compound of the invention are those of the formula (I) in which Ring A is 2-pyridyl group or a 3-(C₁₋₄ alkyl)-2-pyridyl group; Ring B is a 2-(C₁₋₄ alkyl)aminophenyl group; R¹ and R² are hydrogen atom or are combined together to form trimethylene group; m is 1; and n is 0. While the compound (I) of the present invention in which m is 1 may exist in the form of two optically active isomers due to an asymmetric sulfoxide group, the present invention includes within its scope either one of these isomers and a mixture thereof. According to the present invention, the compound (I) or a salt thereof can be prepared by the steps of: i) condensing a mercaptoimidazole compound of the formula: wherein Ring A, R¹ R² and n are the same as defined above, or a salt thereof with a toluene compound of the formula: wherein X is a reactive residue and Ring B is the same as defined above, or a salt thereof, ii) oxidizing the resultant product of the formula: wherein Ring A, Ring B, R¹, R² and n are the same as defined above, and iii) if required, further converting the product into a salt thereof. Alternatively, the compound (I) in which R¹ and R² are combined together to form a group of the formula: -(CH₂) q - (wherein q is the same as defined above) or a salt thereof can be prepared by the steps of: iv) dehydrating a compound of the formula: wherein R¹¹ and R²¹ are combined together to form a group of the formula: -(CH₂) q - and Ring A, Ring B, q and n are the same as defined above, v) oxidizing the resultant product, and vi) if required, further converting the product into a salt thereof. The condensation of the mercaptoimidazole compound (III) and the toluene compound (IV) can be conducted in the presence or absence of an acid acceptor in an inert solvent. Any groups which enable to form C-S bond through reaction with a mercapto group can be used as the reactive residue "X" of the toluene compound (IV). Such reactive residue X includes, for example, a halogen atom, an alkylsulfonyloxy group (e.g., methylsulfonyloxy group), an arylsulfonyloxy group (e.g., toluenesulfonyloxy group, benzenesulfonyloxy group) and the like. The compound (IV) which has amino group, a N-substituted amino group and the like on the benzene ring may, if required, be used for the reaction in the form of an organic or inorganic acid addition salt such as hydrochloride, hydrobromide, sulfate, nitrate, formate, oxalate or methanesulfonate. On the other hand, the compound (III) may, if required, be used for the reaction in the form of an organic or inorganic acid addition salt (e.g., hydrochloride, hydrobromide, sulfate, nitrate, formate, oxalate or methanesulfonate), an alkali metal salt (e.g., sodium salt or potassium salt), an alkaline earth metal salt (e.g., calcium salt or magnesium salt), and a quaternary ammonium salt (e.g., tetramethylammonium salt). A lower alkanol, dimethylformamide, dimethylsulfoxide, water and the mixture thereof are suitable as the solvent. Suitable examples of the acid acceptor include inorganic bases such as an alkali metal hydroxide, an alkali earth metal hydroxide, an alkali metal carbonate, an alkali metal bicarbonate, an alkali metal alkoxide, an alkali metal amide, an alkali metal fluoride, an alkali metal hydride, or organic bases such as pyridine, a tri-lower alkylamine, a lower alkyl lithium, a quaternary ammonium hydroxide (e.g., tetra n-butyl ammonium hydroxide), and the like. It is preferred to carry out the reaction at -20°C to 170 °C, especially -10 to 100°C. On the other hand, the dehydration of the imidazole derivative (V) can be conducted in the presence of a dehydrating agent in an inert solvent. Suitable examples of the dehydrating agent include organic acids such as formic acid, trifluoroacetic acid, p-toluenesulfonic acid, benzenesulfonic acid or camphorsulfonic acid, mineral acids such as hydrochloric acid or sulfonic acid or a mixture of a halogenating agent ( e.g., phosphrus tribromide, phosphorus trichloride or phosphorus oxychloride ) and a base ( e.g., pyridine or triethylamine) and the like. The compound (V) may, if required, be used for the reaction in the form of an organic or inorganic acid addition salt such as hydrochloride, hydrobromide, sulfate, nitrate, formate, oxalate or methanesulfonate. It is preferred to carry out the reaction at -20 °C to 150 °C, especially -10 °C to 100 °C. The oxidation of the above-obtained compound (II) [including the dehydration product of the imidazole derivative (V)] is conducted by treating it with an oxidative agent. Conventional oxidative agents such as peroxy acids (e.g., m-chloroperbenzoic acid, perbenzoic acid or peracetic acid), an alkali metal hypochlorite, an alkali metal chlorite, an alkali metal periodate, tetra n-butyl ammonium periodate, tert.- butyl hydroperoxide, iodoxybenzene, and the like can be used for the reaction. A lower alkanol, methylene chloride, chloroform, tetrahydrofuran, dioxane, water and the mixture thereof are suitable as the solvent. It is preferred to carry out the reaction at -70 °C to 100 °C, especially -50 °C to 20 °C. In this reaction, a sulfinyl-imidazole compound (I) ( m = 1 ) is obtained by using an equimolar amount or a little excess amount of the oxidative agent, and a sulfonyl-imidazole compound (I) ( m = 2 ) is obtained by using not less than two equimolar amount of the oxidative agent. The intermediate (II) obtained by the above-mentioned reaction is a novel compound, and the substituent(s) on the Ring A and/or B thereof may be, if required, modified or converted to other substituent(s) before the oxidation step. For example, the compound (II) having amino group on the Ring A and/or B may be obtained by conventional reduction of the compound (II) having nitro group thereon, or by hydrolysis of the corresponding N-phthalimido or N-tri lower alkylphenylsulfonylamido compound (II). Alternatively, the compound (II) having one or two substituent(s) selected from a lower alkanoylamino group, a lower alkylsulfonylamino group, formylamino group, a lower alkylamino group, an arylcarbonylamino group, a lower alkoxycarbonylamino group and a substituted phenylsulfonylamino group on the Ring A and/or B thereof may be obtained by conventional acylation or alkylation of the compound (II) having amino group, an N-alkylamino group or an N-acylamino group on said Ring A and/or B. Because of the potent inhibitory effect against gastric acid secretion and/or potent inhibitory effect on the enzymatic activity of H⁺/K⁺ ATPase, the imidazole compound (I) of the present invention and a salt thereof are useful for therapeutic treatment and/or prophylaxis of peptic ulcer diseases such as gastric ulcer and duodenal ulcer. The imidazole compound (I) and a salt thereof can be used without unfavorable side effects such an anti-androgen or prolactin release-stimulating effects as observed in histamine H₂-receptor blockers. Moreover, since the imidazole compound (I) and a salt thereof may include a group of compounds which inhibit effectively the gastric acid secretion without affecting the enzyme activity of H⁺/K⁺ ATPase, such compounds may be used as anti-ulcer agents which are different in mechanism of action from the known H⁺/K⁺ ATPase inhibitors such as omeprazole. The compound (I) can be used for pharmaceutical use either in the free form or in the form of a salt thereof. Suitable salts of the compound (I) for pharmaceutical use include, for example, pharmaceutically acceptable salts such as inorganic acid addition salts (e.g., hydrochloride, hydrobromide, hydroiodide, sulfate, nitrate), organic acid addition salts (e.g., formate, oxalate, methanesulfonate, glucuronate), and the like. Such salts may be obtained by treating the free base of the compound (I) with a stoichiometrically equimolar amount of the acid. The dose of the compound (I) or a salt thereof may vary depending on the age, condition and body weight of patients, the kind and severity of diseases to be treated and administration route, etc, but may usually be about 0.05 to about 50 mg/kg, preferably about 0.1 to about 20 mg/kg, per day. The compound (I) and a salt thereof may be administered either orally or parenterally. When administrated orally, the pharmaceutical preparation may be in the solid form such as tablets, powders, capsules or suppositories. These preparations may contain pharmaceutical excipient, binder, diluent, disintegrator or lubricant. The pharmaceutical preparation for oral administration may also be in liquid form such as aqueous or oily suspension, solution, sirup or elixir. Moreover, when administered parenterally, the pharmaceutical preparation may be used in the form of injections. Concomitantly, the starting compound (III) in which R¹ and R² are hydrogen atom may be prepared by the steps of reacting a pyridine compound of the formula: wherein Ring A and n are the same as defined above, with a iso (thio ) cyanate compound of the formula: Z=C=NCH₂CH(OR³)₂ (VII) wherein R³ is an alkyl group and Z is oxygen atom or sulfur atom, in an inert solvent, treating the thus-obtained ( thio ) urea compound with an organic or inorganic acid to give the corresponding cyclic compound, and when Z is oxgen atom, further treating the cyclic compound with a sulfur agent such as Lawesson's Reagent [2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide], 2,4-diethoxy-1,3-dithia-2,4-diphosphetane-2,4-disulfide or phosphorus petasulfide. Alternatively, the starting compound (III) in which R¹ and R² are combined together to form a group of the formula: - (CH₂) q -, ( wherein q is the same as defined above) may be prepared by condensing 2-aminocyclohexanone or 2-aminocyclopentanone with a compound of the formula: wherein Ring A and n are the same as defined above, in the presence of triethylamine, and dehydrating the product in the same manner as described in the dehydration reaction of the imidazole derivative (V). The starting compound (V) may be prepared by condensing 2-aminocyclohexanone or 2-aminocyclopentanone with the compound (VIII) in the presence of triethylamine, and then condensing the product with the toluene compound (IV). Practical and presently preferred embodiments of the present invention are illustratively shown in the following Examples. Example 1 (1) 3.0 g of 1-(2-pyridyl)-2-mercaptoimidazole are dissolved in 50 ml of ethanol, and 16.9 ml of a 2N- aqueous sodium hydroxide solution are added thereto under ice-cooling. 3.84 g of m-dimethylaminobenzyl chloride hydrochloride are added to the mixture and stirred at room temperature for 2 hours. After the solvent is distilled off, water is added to the residue, and the mixture is extracted with ethyl acetate. The extract is washed with water, dried and evaporated to remove the solvent. The residue is recrystallized from a mixture of ethyl acetate and n-hexane, whereby 3.95 g of 1-(2-pyridyl)-2-(3-dimethylaminobenzylthio)imidazole are obtained. Yield 75% M.p. 79-80°C (2) A solution of 3.73 g of the product obtained above in 100 ml of methylene chloride is cooled to -40 °C under argon gas atmosphere. 5.32 g of 80% m-chloroperbenzoic acid are added thereto gradually. The mixture is stirred at the same temperature for 1 hour. The reaction mixture is washed with a saturated aqueous sodium bicarbonate solution, dried and evaporated to remove the solvent. The residue is recrystallized from methanol, whereby 1.48 g of 1-(2-pyridyl)-2-(3-dimethylaminobenzylsulfinyl)imidazole are obtained. Yield 55% M.p. 177-179°C Examples 3 to 25 (1) The corresponding starting compounds are treated in the same manner as described in Example 1-(1) to give the compounds shown in Table 1. (2) The products obtained above are treated in the same manner as described in Example 1-(2) to give the compounds shown in Table 2. Examples 26 to 31 (1) The corresponding starting compounds are treated in the same manner as described in Example 1-(1) to give the compounds shown in Table 3. (2) The products obtained above are treated in the same manner as described in Example 1-(2) to give the compounds shown in Table 4. Examples 35 to 50 (1) The corresponding starting compounds are treated in the same manner as described in Example 1-(1) to give the compounds shown in Table 5. (2) The products obtained above are treated in the same manner as described in Example 1-(2) to give the compounds shown in Table 6. Example 59 (1) The corresponding starting compound is treated in the same manner as described in Example 1-(1) to give the compound shown in Table 9. (2) The product obtained above is treated in the same manner as described in Example 1-(2) to give the compound shown in Table 10. Examples 65 to 66 (1) The corresponding starting compounds are treated in the same manner as described in Example 1-(1) to give the compounds shown in Table 11. (2) The products obtained above are treated in the same manner as described in Example 1-(2) to give the compounds shown in Table 10. Example 67 (1) A solution of 7.53 g of 2-(2-dimethylaminobenzylthio)-1,3a,4,5,6,6a-hexahydro-6a-hydroxy-1-(2-pyridyl)cyclopenta[d]imidazole and a catalytic amount of p-toluenesulfonic acid in 100 ml of toluene is refluxed for 1 hour. The reaction mixture is evaporated to remove the solvent, water is added to the residue, and the aqueous mixture is neutralized with an aqueous sodium bicarbonate solution. The mixture is extracted with chloroform. The extract is dried and evaporated to remove the solvent, whereby 3.94 g of 1,4,5,6-tetrahydro-2-(2-dimethylaminobenzylthio)-1-(2-pyridyl)cyclopenta[d]imidazole are obtained. Yield 55% M.p. 115 to 117°C (recrystallized from ethyl acetate and n-hexane) (2) The product obtained above is treated in the same manner as described in Example 1-(2) to give 1,4,5,6-tetrahydro-2-(2-dimethylaminobenzylsulfinyl)-1-(2-pyridyl)cyclopenta[d]imidazole. Yield 74%. M.p. 139.5 to 141°C (recrystallized from ethyl acetate and n-hexane) Examples 68 to 70 (1) The corresponding starting compounds are treated in the same manner as described in Example 67-(1) to give the compounds shown in Table 13. (2) The products obtained above are treated in the same manner as described in Example 1-(2) to give the compounds shown in Table 14. Example 71 (1) 1-(2-pyridyl)-2-mercaptoimidazole and (2,4,6-trimethylphenyl)sulfonylaminobenzyl chloride are treated in the same manner as described in Example 1-(1) to give 1-(2-pyridyl)-2-[2-(2,4,6-trimethylphenyl)sulfonylaminobenzylthio]imidazole. Yield 87% M.p. 154 to 156 °C (recrystallized from isopropyl alcohol) (2) A mixture of 2 g of the product obtained above, 2.5 ml of anisole and 15 ml of methanesulfonic acid is stirred at room temperature for 20 hours. After the reaction, the mixture is added to water and extracted with ethyl acetate. The extract is washed with a saturated aqueous sodium chloride solution, dried and evaporated to remove the solvent, whereby 1.1 g of 1-(2-pyridyl)-2-(2-aminobenzylthio)imidazole are obtained as an oil Yield 93% Mass (m/e):282(M⁺), 106 ¹H-MNR (CDCl₃,δ):3.9(br,2H,NH₂),4.43(s,2H,SCH₂) (3) The product obtained above is treated in the same manner as described in Example 1-(2) to give 1-(2-pyridyl)-2-(2-aminobenzylsulfinyl)imidazole. M.p. 145 to 146°C (recrystallized from isopropyl alcohol) Example 73 (1) 100 mg of 60% sodium hydride are suspended in 2 ml of dimethyl formamide, and a solution of one g of 1-(2-pyridyl)-2-[2-(2,4,6-trimethylphenyl)sulfonylaminobenzylthio]imidazole in 2 ml of dimethyl formamide is added thereto under ice-cooling. The mixture is stirred at room temperature for 30 minutes, and 320 mg of methyl iodide are added thereto. The mixture is stirred for 2 hours. The reaction mixture is poured into water, and the resultant oily product is extracted with ethyl acetate. The extract is dried and evaporated. The residue is purified by silica gel column chromatography ( solvent; n-hexane : ethyl acetate = 3 : 2 ), whereby 0.76 g of 1-(2-pyridyl)-2-{2-[N-methyl-N-(2,4,6-trimethylphenyl)sulfonylamino]benzylthio}imidazole is obtained. M.p. 131 to 133°C ( recrystallized from ethyl acetate) (2) The product obtained above is treated in the same manner as described in Example 71-(2) to give 1-(2-pyridyl)-2-(2-methylaminobenzylthio)imidazole as an oil. Yield 92% Mass(m/e):296(M⁺), 120 ¹H-NMR(CDCl₃,δ):2.83(d,3H,J=3Hz,NCH₃),4.42(s,2H,SCH₂), 5.20(br,1H,NH) (3) The product obtained above is treated in the same manner as described in Example 1-(2) to give 1-(2-pyridyl)-2-(2-methylaminobenzylsulfinyl)imidazole. M.p. 135 to 137°C ( recrystallized from ethyl acetate) Example 77 (1) 1-(2-pyridylmethyl)-2-mercaptoimidazole and 2-phthalimidobenzyl chloride are treated in the same manner as described in Example 1-(1) to give 1-(2-pyridylmethyl)-2-(2-phthalimidobenzylthio)imidazole. M.p. 80 to 83°C (recrystallized from ethanol) (2) The product obtained above is treated in the same manner as described in Example 75-(2) to give 1-(2-pyridylmethyl)-2-(2-aminobenzylthio)imidazole as an oil. Mass(m/e):296(M⁺), 106 ¹H-NMR(CDCl₃,δ):4.21(s,2H,SCH₂),4.31(br,2H,NH₂), 5.10(s,2H,NCH₂) (3) The product obtained above is treated in the same manner as described in Example 1-(2) to give 1-(2-pyridylmethyl)-2-(2-aminobenzylsulfinyl)imidazole. Mass(m/e):312(M⁺), 106 ¹H-NMR(CDCl₃,δ):4.26(br,2H,NH₂),4.59(ABq,2H,NCH₂), 5.29(ABq,2H,NCH₂) Example 101 (1) 3.26 g of 1-(3-hydroxy-2-pyridyl)-2-(2-dimethylaminobenzylthio)imidazole are dissolved in 100 ml of dimethyl formamide, and 0.48 g of 60% sodium hydride is added thereto. After the mixture is stirred for 20 minutes, 1.3 ml of isopropyl bromide are added dropwised thereto, and the mixture is further stirred at room temperature for 17 hours. The reaction mixture is poured into ice water, extracted with ethyl acetate, dried and evaporated to remove the solvent. The residue is recrystallized from a mixture of ethyl acetate and n-hexane, whereby 2.47 g of 1-(3-isopropoxy-2-pyridyl)-2-(2-dimethylaminobenzylthio)imidazole are obtained. Yield 67% M.p. 85 to 87°C (2) The product obtained above is treated in the same manner as described in Example 1-(2) to give 1-(3-isopropoxy-2-pyridyl)-2-(2-dimethylaminobenzylsulfinyl)imidazole. Mass(m/e):384(M⁺), 134 ¹H-NMR(CDCl₃,δ): 1.32 and 1.34 ( d, 3H, CH₃, respectively), 2.63(s,6H,N(CH₃)₂),4.81(ABq,2H,SCH₂) Examples 102 (1) The corresponding starting compounds are treated in the same manner as described in Example 101-(1) to give the compounds shown in Table 23. (2) The product obtained above is treated in the same manner as described in Example 1-(2) to give the compound shown in Table 24. [Preparation of starting compounds] Preparation 1 (1) A solution of 3.76 g of 2-aminopyridine and 7 g of 2,2-diethoxyethyl isothiocyanate in toluene is refluxed. After the reaction, the solvent is distilled off, and the residue is recrystallized from a mixture of ethyl acetate and n-hexane, whereby 9 g of N-(2,2-diethoxyethyl)-N'-(2-pyridyl)thiourea are obtained. M.p. 126 to 128 °C (2) A solution of 8.94 g of the product obtained above and a small amount of conc. hydrochloric acid in acetic acid is refluxed. After the reaction, the solution is evaporated to remove the solvent. The residue is dissolved in water, and sodium bicarbonate is added thereto. The crystalline precipitates are collected by filtration, whereby 4.91 g of 1-(2-pyridyl)-2-mercaptoimidazole are obtained. M.p. 159 to 161 °C ( recrystallized from isopropyl alcohol, isopropyl ether and n-hexane) Preparations 2 to 25 The corresponding starting compounds are treated in the same manner as described in Preparation 1-(1) and (2) to give the compounds shown in Table 25. Preparation 26 (1) A solution of 57.96 g of o-dimethylcarbamoylbenzoic acid in tetrahydrofuran is added dropwise to a tetrahydrofuran suspension of 34.05 g of sodium borohydride. After the reaction at room temperature, 170.3 g of boron trifluoride etherate are added dropwise thereto, and the mixture is further refluxed. After cooling, a solution of 54 g of oxalic acid in water and methanol is added thereto, and the mixture is further refluxed. The reaction mixture is condensed and extracted with ethyl acetate under an alkaline condition. The extract is evaporated to remove the solvent, and the residue is distilled under reduced pressure, whereby 19.04 g of o-dimethylaminomethylbenzyl alcohol are obtained. B.p. 106 to 109 °C ( 4mmHg ) (2) 2.89 g of thionyl chloride are added dropwise to a methylene chloride solution of 2.9 g of the product obtained above. After the reaction at room temperature, the mixture is diluted with ether. The crystalline precipitates are collected by filtration, whereby 3.78 g of o-dimethylaminomethylbenzylchloride hydrochloride are obtained. M.p. 143 to 147°C Preparation 27 (1) To a tetrahydrofuran solution of 5.12 g of N-phenylanthranilic acid, 32.2 ml of a hexane solution of n-butyl lithium and a solution of 4.42 g of methyl iodide in tetrahydrofuran are added successively at -60°C and the mixture is reacted at room temperature. After the reaction, water is added thereto, and the aqueous mixture is extracted with ethyl acetate under an acidic condition. The extract is evaporated to remove the solvent, whereby 5.06 g of N-methyl-N-phenyl anthranilic acid are obtained as an oil. Yield 93% Mass(m/e):227(M⁺) ¹H-NMR(CDCl₃,δ): 3.22(s,3H,NCH₃) (2) A solution of 5.06 g of N-methyl-N-phenyl anthranilic acid in tetrahydrofuran is added dropwise to a tetrahydrofuran suspension of 1.7 g of lithium alminum hydride under ice-cooling. After the reaction at room temperature, the mixture is cooled in an ice bath. Water and a saturated aqueous sodium sulfate solution are added to the mixture, and insoluble materials are filtered off. The filtrate is evaporated to remove the solvent, and the residue is purified by silica gel column chromatography, whereby 4.33 g of o-N-methyl-N- phenylaminobenzyl alcohol are obtained as a colorless oil. Mass(m/e):213(M⁺) ¹H-NMR(CDCl₃,δ): 2.10(t,1H,J=6Hz,OH),3.21(s,3H,NCH₃), 4.56(d,2H,J=6Hz,CH₂O) Preparation 28 A solution of 9 g of ethyl o-(1-pyrrolyl)benzoate in ether is added dropwise to an ether suspension of 2.4 g of lithium alminum hydride under ice-cooling. After the reaction, water and a saturated aqueous sodium sulfate solution are added to the mixture, and insoluble materials are filtered off. The filtrate is evaporated to remove the solvent, and the residue is distilled under reduced pressure, whereby 6.3 g of o-(1-pyrrolyl)benzyl alcohol are obtained. B.p. 120 to 135°C( 3 to 4 mmHg Mass(m/e):173(M⁺) ¹H-NMR(CDCl₃,δ): 4.52(s,2H,CH₂O), 6.30 and 6.83 Preparation 29 A mixture of 6.82 g of 2-aminocyclohexanone hydrochloride, 6.21 g of 2-pyridylisothiocyanate dimer and 100 ml of toluene is stirred under heating. When the temperature is cooled down to 50°C, 4.61 g of triethylamine are added dropwise thereto. after the reaction, water is added to the reaction mixture, and the aqueous mixture is extracted with ethyl acetate. The extract is washed with a saturated sodium chloride solution, dried and evaporated to remove the solvent, whereby 8.2 g of N-(2-pyridyl)-N'-(2-oxocyclohexyl)thiourea are obtained. Yield 72% M.p. 149 to 151 °C Preparation 30 2-aminocyclopentanone hydrochloride is treated in the same manner as described in Preparation 29 to give 2-mercapto-1,3a,4,5,6,6a-hexahydro-6a-hydroxy-1-(2-pyridil)cyclopenta[d]imidazole. Yield 55% M.p. 126 to 127 °C Preparation 31 N-(2-pyridyl)-N'-(2-oxocyclohexyl)thiourea is treated in the same manner as described in Example 67-(1) to give 1-(2-pyridyl)-4,5,6,7-tetrahydrobenzimidazol-2-thione. M.p. 203 to 204 °C (recrystallized from ethyl acetate and n-hexane) Preparations 32 to 36 2-mercapto-1,3a,4,5,6,6a-hexahydro-6a-hydroxy-1-(2-pyridyl)cyclopenta[d]imidazole and the corresponding starting compounds are treated in the same manner as described in Example 1-(1) to give the compounds shown in Table 26. Preparation 37 (1) 24.2 g of ethyl o-fluorobenzoate and 9.8 g of imidazole are heated in the presence of sodium hydride, whereby 23 g of ethyl o-imidazolylbenzoate are obtained. B.p. 165 to 167 °C (2 mmHg) (2) 5 g of the product obtained above are treated in the same manner as described in Preparation 28 to give 3.4 g of o-imidazolylbenzyl alcohol. (3) 3.4 g of the product obtained above are treated in the same manner as described in Preparation 26-(2) to give 3.3 g of o-imiazolylbenzyl chloride are obtained. M.p. 160 to 161 °C ( recrystallized from ethanol and ether )

Claims: Claims for the following Contracting States : AT, BE, CH, DE, GB, IT, LI, LU, NL, SE An imidazole derivative of general formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹ and R² are hydrogen atoms or are combined together to form a group of the formula: -(CH₂) q -; m is 1; n is 0 or 1; and q is 3 or 4, or a pharmaceutically acceptable acid addition salt thereof. A compound according to Claim 1, in which Ring A is a 2- or 4-pyridyl group, a 3-(C₁₋₄ alkoxy)-2-pyridyl group or a 3- or 4-(C₁₋₄ alkyl)-2-pyridyl group; and Ring B is a 2-morpholinophenyl group, a 2-aminophenyl group, a 2-mono(C₁₋₄ alkyl)aminophenyl group or a 2-di(C₁₋₄ alkyl)aminophenyl group. A compound according to Claim 2, in which Ring A is a 2- or 4-pyridyl group, a 3-methoxy-2-pyridyl group or a 3- or 4-methyl-2-pyridyl group; and Ring B is a 2-morpholinophenyl group, a 2-aminophenyl group, a 2-methylaminophenyl group, a 2-ethylaminophenyl group, a 2-dimethylaminophenyl group or a 2-diethylaminophenyl group. A compound according to Claim 1, wherein Ring A is a (C₁₋₄ alkyl)-2-pyridyl group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl) amino group; R¹ and R² are hydrogen atoms or are combined together to form a trimethylene group; and n is 0. A compound according to Claim 4, wherein Ring A is a 3-(C₁₋₄ alkyl)-2-pyridyl group; and Ring B is a 2-aminophenyl group, a 2-mono-(C₁₋₄ alkyl)aminophenyl group or a 2-di(C₁₋₄ alkyl)aminophenyl group. A compound according to Claim 5, wherein Ring A is a 3-methyl-2-pyridyl group; and Ring B is a 2-aminophenyl group, a 2-methylaminophenyl group or a 2-dimethylaminophenyl group. A compound according to Claim 5, in which Ring B is a 2-di(C₁₋₄ alkyl)aminophenyl group. A compound according to Claim 6 in which Ring B is 2-dimethylaminophenyl group and R¹ and R² are combined together to form a trimethylene group. A compound according to Claim 6, which is 1-(3-methyl-2-pyridyl)-2-[2-(dimethylamino)benzylsulfinyl]imidazole or a pharmaceutically acceptable acid addition salt thereof. A compound according to any preceding claim for use in a method of therapy. A compound according to any of claims 1-9 for use in the treatment or prevention of ulcers. A process for the preparation of an imidazole derivative of the formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹ and R² are hydrogen atoms or are combined together to form a group of the formula: -(CH₂) q -; m is 1; n is 0 or 1; and q is 3 or 4, or a sale thereof, which comprises oxidizing an imidazole derivative of the formula: wherein Ring A, Ring B, R¹, R² and n are the same as defined above, or a salt thereof, and, if required, further converting the product into a salt thereof. A process for the preparation of an imidazole derivative of the formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹ and R² are hydrogen atoms or are combined together to form a group of the formula: -(CH₂) q -; m is 1; n is 0 or 1; and q is 3 or 4, or a salt thereof, which comprises the steps of: condensing a mercaptoimidazole compound of the formula: wherein Ring A, R¹, R² and n are the same as defined above, or a salt thereof with a toluene compound of the formula: wherein X is a reactive residue, and Ring B is the same as defined above, or a salt thereof, oxidizing the resultant product of the formula: wherein Ring A, Ring B, R¹, R² and n are the same as defined above, and if required, further converting the product into a salt thereof. A process for the preparation of an imidazole derivative of the formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹¹ and R²¹ are combined together to form a group of the formula: -(CH₂) q -; m is 1; n is 0 or 1; and q is 3 or 4, or a salt thereof, which comprises the steps of: dehydrating a compound of the formula: wherein R¹¹, R²¹, Ring A, Ring B, and n are the same as defined above, oxidizing the resultant product of the formula: wherein Ring A, Ring B, R¹¹, R²¹ and n are the same as defined above, and if required, further converting the product into a salt thereof. A pharmaceutical composition which comprises a pharmaceutically effective amount of a compound according to any of claims 1-9 and a pharmaceutically acceptable carrier. The use of a compound according to any of claims 1-9 for the manufacture of a medicament for the treatment or prevention of ulcers. An imidazole derivative of the formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹ and R² are hydrogen atoms or are combined together to form a group of the formula: -(CH₂) q -; n is 0 or 1; and q is 3 or 4, or a salt thereof. Claims for the following Contracting States : ES, GR The use of an imidazole derivative of general formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹ and R² are hydrogen atoms or are combined together to form a group of the formula: -(CH₂) q -; m is 1; n is 0 or 1; and q is 3 or 4, or a pharmaceutically acceptable acid addition salt thereof, for the manufacture of a medicament for the treatment or prevention of ulcers. The use according to Claim 1, in which Ring A is a 2- or 4-pyridyl group, a 3-(C₁₋₄ alkoxy)-2-pyridyl group or a 3- or 4-(C₁₋₄ alkyl)-2-pyridyl group; and Ring B is a 2-morpholinophenyl group, a 2-aminophenyl group, a 2-mono(C₁₋₄ alkyl)aminophenyl group or a 2-di(C₁₋₄ alkyl)aminophenyl group. The use according to Claim 2, in which Ring A is a 2- or 4-pyridyl group, a 3-methoxy-2-pyridyl group or a 3- or 4-methyl-2-pyridyl group; and Ring B is a 2-morpholinophenyl group, a 2-aminophenyl group, a 2-methylaminophenyl group, a 2-ethylaminophenyl group, a 2-dimethylaminophenyl group or a 2-diethylaminophenyl group. The use according to Claim 1, wherein Ring A is a (C₁₋₄ alkyl)-2-pyridyl group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl) amino group; R¹ and R² are hydrogen atoms or are combined together to form a trimethylene group; and n is 0. The use according to Claim 4, wherein Ring A is a 3-(C₁₋₄ alkyl)-2-pyridyl group; and Ring B is a 2-aminophenyl group, a 2-mono-(C₁₋₄ alkyl)aminophenyl group or a 2-di(C₁₋₄ alkyl)aminophenyl group. The use according to Claim 5, wherein Ring A is a 3-methyl-2-pyridyl group; and Ring B is a 2-aminophenyl group, a 2-methylaminophenyl group or a 2-dimethylaminophenyl group. The use according to Claim 5, in which Ring B is a 2-di(C₁₋₄ alkyl)aminophenyl group. The use according to Claim 6 in which Ring B is 2-dimethylaminophenyl group and R¹ and R² are combined together to form a trimethylene group. The use according to Claim 6, wherein the imidazole derivative is 1-(3-methyl-2-pyridyl)-2-[2-(dimethylamino)- benzylsulfinyl]imidazole or a pharmaceutically acceptable acid addition salt thereof. A process for the preparation of an imidazole derivative of the formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹ and R² are hydrogen atoms or are combined together to form a group of the formula: -(CH₂) q -; m is 1; n is 0 or 1; and q is 3 or 4, or a salt thereof, which comprises oxidizing an imidazole derivative of the formula: wherein Ring A, Ring B, R¹, R² and n are the same as defined above, or a salt thereof, and, if required, further converting the product into a salt thereof. A process for the preparation of an imidazole derivative of the formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹ and R² are hydrogen atoms or are combined together to form a group of the formula: -(CH₂) q -; m is 1; n is 0 or 1; and q is 3 or 4, or a salt thereof, which comprises the steps of: condensing a mercaptoimidazole compound of the formula: wherein Ring A, R¹, R² and n are the same as defined above, or a salt thereof with a toluene compound of the formula: wherein X is a reactive residue, and Ring B is the same as defined above, or a salt thereof, oxidizing the resultant product of the formula: wherein Ring A, Ring B, R¹, R² and n are the same as defined above, and if required, further converting the product into a salt thereof. A process for the preparation of an imidazole derivative of the formula: wherein Ring A is a 2- or 4-pyridyl group or a 2- or 4-pyridyl group having a substituent selected from a C₁₋₄ alkyl group and a C₁₋₄ alkoxy group; Ring B is a phenyl group having one substituent selected from an amino group, a mono(C₁₋₄ alkyl)amino group, a di(C₁₋₄ alkyl)amino group, and a morpholino group; R¹¹ and R²¹ are combined together to form a group of the formula: -(CH₂) q -; m is 1; n is 0 or 1; and q is 3 or 4, or a salt thereof, which comprises the steps of: dehydrating a compound of the formula: wherein R¹¹, R²¹, Ring A, Ring B, and n are the same as defined above, oxidizing the resultant product of the formula: wherein Ring A, Ring B, R¹¹, R²¹ and n are the same as defined above, and if required, further converting the product into a salt thereof.

Inventors: HONMA, YASUSHI, MAGARIBUCHI, TETSUO, TAKIDO, MINE, TAMAKI, HAJIME
Applicants: TANABE SEIYAKU CO., LTD.
Application year: 1987
Main classification: C07D401
IPC codes: A61K31, C07D401, C07D521, A61P1