A CYCLOHEXANEDIONE DERIVATIVE AND A PROCESS FOR PRODUCING THE SAME

Abstract: A cyclohexanedione derivative represented by the general formula (I); wherein R¹, R⁴ and R⁷ represent independently hydrogen atom or C₁ - C₈ alkyl group, R² represents hydrogen atom; C₁ - C₈ alkyl group; C₂ - C₆ alkenyl group; C₃ - C₈ cycloalkyl group; C₂ - C₇ alkoxycarbonyl group; C₁ - C₆ alkylthio C₁ - C₆ alkyl group; a phenyl group; a phenyl group substituted with 1 to 3 groups selected from th e group consisting of halogen atom, C₁ - c₆ alkyl group, C₁ - C₆ haloalkyl group, C₁ - C₆ alkoxy group, C₁ - C₆ alkylthio group, C₃ - C₈ cycloalkoxy group, a benzyloxy group and a benzyloxy group substituted with C₁ - C₆ alkoxy group; naphthyl group or heterocyclic group, R³ represents hydrogen atom, C₁ - C₈ alkyl group or C₂ - C₇ alkoxycarbonyl group, and R⁵ and R⁶, which may be the same or different, represent hydrogen atom, C₁ - C₆ alkyl group, C₂ - C₆ alkenyl group, C₂ - C₇ alkylcarbonyl group or C₂ - C₇ haloalkylcarbonyl group or its pharmaceutically acceptable salts; a pharmaceutical composition containing the same; and a process for producing the same.

Description: This invention relates to new cyclohexanedione derivatives, pharmaceutical compositions containing same and a method for preparing the cyclohexanedione derivatives. BACKGROUND OF THE INVENTION It has been disclosed that cyclohexanedione derivatives shown below are effective for the treatment of liver damage (see U.S. Patent No. 4,668,799) 1. 2-(1,3-dithiol-2-ylidene)-1,3-cyclohexanedione; 2. 2-(1,3-dithiol-2-ylidene)-4-methyl-1,3-cyclohexanedione; 3. 2-(1,3-dithiol-2-ylidene)-4-(2-methylethyl)-1,3-cyclohexanedione; 4. 2-(1,3-dithiol-2-ylidene)-5,5-dimethyl-1,3-cyclohexanedione. There is still a desire, however, for a compound capable of curing and/or preventing liver disorders at a considerably lower dosage which will provide a more safety margin for treating both men and animals. SUMMARY OF THE INVENTION It is an object of the present invention to provide a new cyclohexanedione derivative useful for curing and/or preventing liver disorders and a method for preparing same. Another object of the present invention is to provide a pharmaceutical composition, in particular, for treating hepatic disorders, containing as an active ingredient the new cyclohexanedione derivative. This invention relates to a cyclohexanedione derivative represented by the general formula wherein R¹, R⁴ and R⁷ represent independently hydrogen atom or C₁ - C₈ alkyl group, R² represents hydrogen atom; C₁ - C₈ alkyl group; C₂ - C₁₆ alkenyl group; C₃ - C₈ cycloalkyl group; C₂ - C₇ alkoxycarbonyl group; C₁ - C₆ alkylthio C₁ - C₆ alkyl group; a phenyl group; a phenyl group substituted with 1 to 3 groups selected from the group consisting of halogen atom, C₁ - C₆ alkyl group, C₁ - C₆ haloalkyl group, C₁ - C₆ alkoxy group, C₁ - C₆ alkylthio group, C₃ - C₈ cycloalkoxy group, a benzyloxy group and a benzyloxy group substituted with C₁ - C₆ alkoxy group; naphthyl group or a furyl or thienyl group, R³ represents hydrogen atom, C₁ - C₈ alkyl group or C₂ - C₇ alkoxycarbonyl group, and R⁵ and R⁶, which may be the same or different, represent hydrogen atom, C₁ - C₆ alkyl group, C₂ - C₆ alkenyl group, C₂ - C₇ alkylcarbonyl group or C₂ - C₇ haloalkylcarbonyl group and its pharmaceutically acceptable salts, a process for producing the same and a pharmaceutical composition containing the same. The terms "alkyl and alkenyl" as used herein denote both straight-chain and branched alkyl and alkenyl groups, respectively. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The compounds represented by the afore-mentioned general formula (I) and their salts are novel compounds not described in the literatures; they have, for example, a liver function activating effect, and hence are useful as active ingredient for a pharmaceutical composition for treating hepatic disorders in men and animals. The compound of general formula (I) can be produced, for example, by methods A and B as shown in the following scheme: wherein R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ have the same meanings as defined above, M represents alkali metal atom. That is, the compound of the general formula (I) can be produced by reacting the compound of the general formula (II) with the compound of the general formula (III) in a suitable solvent at a temperature in the range of from -20°C to 50°C and followed by the reaction with the compound of the general formula (IV) at a temperature in the range of from -20°C to 80°C. The solvents which can be used in the present reaction are preferably water or solvents consisting of water and an organic solvent. Said organic solvent can be, for example, dimethylformamide, dimethylsulfoxide, hexamethylphosphoroamide and N,N-dimethylethyleneurea or in combination of these solvents. The reaction time depends upon the reaction temperature and reaction scale, but it may properly be selected from 1 to 24 hours. As to the molar ratio of the reagents in practicing the present reaction, they are used in equimolar amounts because the present reaction is an equimolar reaction, but either one of them may be used in excess of the other. The compound of general formula (II) shown below can be obtained by reacting a compound of general formula (V) with an equivalent or a slightly excess of sodium bisulfite in water at a temperature in the range of from 0°C to 80°C. wherein R⁴ has the same meaning as defined above. The compound of the general formula (IV) shown below can be obtained by reacting a compound of general formula (VI) with carbon disulfide in a suitable solvent in the presence of a base at a temperature in the range of from -20°C to 60°C: wherein R¹, R², R³ and M have the same meaning as defined above. In most cases, the compound of the general formula (IV) can be used without being separated from the reaction mixture. Bases usable in preparing the compound of the general formula (IV) are, for example, a hydroxide such as sodium hydroxide, potassium hydroxide and a carbonate such as sodium carbonate, potassium carbonate. For a solvent, there can be used, for example, dimethylformamide, dimethylsulfoxide, hexamethylphosphoroamide and N,N-dimethylethyleneurea, and in combination of these solvents or in combination of water with above organic solvents. wherein R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ have the same meanings as defined above, R⁸ represents hydrogen atom or C₁ - C₅ alkyl group, and X represents halogen atom. That is, the compound of the general formula (I) can be produced by reacting the compound of the general formula (I′), which was prepared by the method A, with the compound of the general formula (VII) or (VIII) in an inert solvent at a temperature in the range of from -20°C to the boiling point of the solvent used. Solvents which can be used in this reaction may be any of those not disturbing the reaction, and include for example ethers (e.g. diethyl ether, tetrahydrofuran, dioxane), aromatic hydrocarbons (e.g. benzene, toluene, xylene), halogenated hydrocarbons (e.g. chloroform, carbon tetrachloride). These solvents may be used alone or in combination. Bases which can be used in this reaction are inorganic bases such as sodium hydroxide, potassium hydroxide, lithium hydride, sodium hydride, etc. and organic bases such as, e.g. triethylamine, pyridine. As to the amount of the base and the compound of the general formula (VII) or (VIII) used in this reaction, it suffices to use 2 mole per mole of the compound of the general formula (I′) when R⁸ represents hydrogen atom in general formula (I′) and an amount equimolar to the compound of the general formula (I′) when R⁸ represents C₁ - C₅ alkyl group, but amounts in excess thereof will do. The reaction time depends upon the reaction temperature and reaction scale, but it may properly be selected from a range of 30 minutes to 8 hours. Further, the salt of the compound of the general formula (I) was obtained by reacting the compound of the general formula (I) with the acid. The salt of the compound of the general formula (I) may be any of pharmaceutically acceptable salt. Acids usable in preparing the salt are, for example, inorganic acids such as hydrogen chloride, sulfuric acid, and phosphoric acid, or organic carboxylic acids such as acetic acid, succinic acid, fumaric acid, tartaric acid and organic sulfonic acids such as methanesulfonic acid, heptanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid. For the solvents, there can be used for example, alcohol, chloroform, dichloromethane, and ethyl acetate. The compound of the general formula (I) and its salt can be separated by a conventional method. Representative examples of the compound of the general formula (I) and their salts will be shown in Table 1, but the derivatives are not limited to these examples. Among the compounds of the present invention of which the typical examples are shown in Table 1 below, the prefered compounds are those whose R² represents hydrogen atom; lower (C₁ - C₆) alkyl group; alkenyl group; cycloalkyl group; a phenyl group; a phenyl group substituted with 1 to 3 groups selected from the group consisting of halogen atom, lower (C₁ - C₆) alkyl group, lower (C₁ - C₆) haloalkoxy group, lower (C₁ - C₆) alkoxy group, cycloalkoxy group, a benzyloxy group and a benzyloxy group substituted with lower (C₁ - C₆) alkoxy group; naphthyl group or a furyl or thienyl group, and R⁵ and R⁶, which may be the same or different, represent hydrogen atom; lower alkyl, lower (C₂ - C₆) alkenyl group, alkylcarbonyl group or haloalkylcarbonyl group. More preferred ones are those whose R² represents hydrogen atom; C₁ - C₄ alkyl group; a phenyl group; a phenyl group substituted with 1 to 2 groups selected from the group consisting of halogen atom, C₁ - C₄ alkyl group and C₁ - C₄ alkoxy group; or furyl group, R³ represents hydrogen atom or C₁ - C₄ alkyl group. The respective melting point of the compound numbers 118-122 in Table 1 shows the value of hydrochloric acid salt of said compounds. Next, NMR spectra data of compound No. 100 is shown below. NMR data (60 MHz, CDCl₃, δ value) 1.12(3H, t, J=7.0Hz), 1.24(3H, d, J=7.0Hz) 1.20-1.70(3H), 2.40(6H, S), 2.0-3.10(11H) 4.35(2H, S) Cyclohexanedione derivatives represented by the general formula (I) and their salts caused no toxic symptom nor death in mice or rats even after administered continually for two weeks at a does of 300 mg/kg/day to the mice or rats, which reveals the markedly low toxicity of the compound of this invention. For example, LD₅₀ value (acute oral toxicity to male rat) of the compound No. 55 is more tan 1,000 mg/kg. The compounds represented by the general formula (I) and their salts are useful as a medicinal agent for treating liver diseases. For example, while it is known that hepatic disorders can be experimentally produced in healthy test animals by administering various agents such as carbon tetrachloride to the animals, as disclosed for example in U.S. Patent No. 4,118,506, it has been found that the compounds represented by the general formula (I) and their salts give a marked effect of suppressing the lowering of liver functions when administered orally or parenterally (for example by injection) to test animals which have hepatic disorders of various pathologic models experimentally produced therein. Accordingly, the compounds represented by the general formula (I) and their salts are useful as a medicinal agent for curing or preventing hepatic disorders in men and animals. Thus, it can be used as a curative for acute or chronic hepatic disorders of men and animals produced by various causes, for example, jecure adiposum, alcoholic hepatitis, hepatitis, toxic liver disorders, cardic cirrhosis, cholestatic liver disorder, or hepatocirrhosis which is the final state of these diseases. Accordingly, the term "a pharmaceutical composition for treating hepatic disorders" as used in this invention means a medicinal agent for curing and/or preventing various disorders in liver by utilizing the pharmacological actions manifested in liver as mentioned above including the action of activating liver functions and the action of preventing and curing hepatic disorders. The compound represented by the general formula (I) or its salt can be used as a medicinal agent for treating hepatic disorders in the form as it is; it may also be formulated, according to conventional pharmaceutical procedures, as a mixture thereof with pharmaceutically acceptable diluents and/or other pharmacologically active substances. Further, it may be formulated into a dose unit form. Examples of the form which the compound can take as a medicinal agent include: powders, granules, tablets, dragée, capsules, pills, suspensions, solutions, liquid, emulsions, ampules, injections, and isotonic solutions. The modes of preparing the compound of this invention into a pharmaceutical composition include one wherein the compound represented by the general formula (I) or its salt is contained as a mixture thereof with one or more pharmaceutically acceptable diluents. The "diluent" referred to herein means a material other than the compound represented by the general formula (I) and their salts. It may be in the form of solid, semisolid, liquid, or ingestible capsules. Examples of the diluents include excipients, fillers, binders, moistening agents, disintegrators, surfactants, lubricants, dispersants, buffering agents, flavoring agents, odor correctives, coloring agents, flavors, preservatives, solubilizing aids, solvents, coating agents, and sugar-coating agents. However, they are not limited to these. Further, they may be used as a mixture of one or more kinds thereof. Sometimes, these pharmaceutically acceptable diluents are used as a mixture thereof with other pharmacologically active substances. The pharmaceutical composition according to this invention may be prepared by any method known in the art. For instance, the active ingredient is mixed with a diluent and made up, for example, into granules. The resulting composition is then formed, for example, into tablets. Preparations to be administered parenterally should be made aseptic. Further, as occasion demands, they should be made isotonic to blood. In this invention, since the compound represented by the general formula (I) and their salts mentioned above can be itself make a medicinal agent for treating liver diseases, the active ingredient is generally contained in the composition in a proportion of 0.01 to 100% by weight. When the compound is made into a preparation in the form of dose unit, the individual parts of the preparation which form said preparation may be either in the same shape or in shapes different from each other. For example, the following shapes are often adopted: tablets, granules, pills, powders, dragée, capsules, ampules, and the like. The medicinal agent for treating hepatic disorders according to this invention can be applied to men and animals for the purpose of preventing and treating hepatic disorders therein in a manner conventional in the art. It is administered orally or parenterally. Oral administration referred to herein includes sublingual administration. Parenteral administration referred to herein includes administrations conducted means of injections (including, for example, subcutaneous, intramuscular or intravenous injection and instillation). The dose of the medicinal agent of this invention varies depending upon various factors including whether it is applied to animals or men, difference in susceptibility, age, sex, body weight, the method, time, and interval of administration, the condition of diseases, physical condition, the properties of the pharmaceutical composition, the kind of the preparation, and the kind of the active ingredient. Accordingly, sometimes those doses may be sufficient which are lower than the minimum of the dose range shown below, whereas sometimes it becomes necessary to administer an amount exceeding the upper limit of the dose shown below. When the pharmaceutical composition is to be administered in a large amount, it is preferably administered divided in several doses per day. In order to obtain effective results in application to animals, the agent is advantageously administered at a dose, in terms of the active ingredient, in the range of 0.1 to 500 mg, preferably 0.1 to 30 mg, per 1 kg of body weight per day in oral administration, and 0.01 to 250 mg, preferably 0.1 to 25 mg, per 1 kg of body weight per day in the case of parenteral administration. The doses necessary for obtaining effective results in application to men are, judged from the effective doses in animals and in consideration of difference in susceptibility and safety, advantageously selected, for example, from the following dose range. In oral administration the dose is 0.1 to 200 mg, preferably 0.5 to 50 mg, per kg of body weight per day, and in parenteral administration it is 0.01 to 100 mg, preferably 0.1 to 25 mg, per kg of body weight per day. Example The following examples illustrate the invention. First, synthesis examples of this invention are shown below. Example 1 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-1,3-cyclohexanedione (compound No. 1) To a suspension of 5.75 g (0.02 mole) of glyoxal-sodium bisulfite in 20 ml of water was added dropwise 1.92 g (0.02 mole) of N,N′-dimethylethylenediamine with ice-cooling and the mixture was stirred until it became a homogeneous solution. Then to this solution was added with ice-cooling the dithiolate solution prepared in the manner shown below: To a mixture of 2.24 g (0.02 mole) of cyclohexanedione and 1.6 g (0.021 mole) of carbon disulfide in 15 ml of dimethylsulfoxide was added with ice-cooling 2.8 g (0.05 mole) of powdered potassium hydroxide and the mixture was stirred for 1 hour. The reaction mixture was stirred, for additional 30 minutes and the crystalline precipitate was collected by filtration. This crystalline was washed with water, isopropylalcohol and hexane, and then recrystallized from isopropylalcohol to give 3.0 g of the desired product. Yield 50%; m.p. 158-159°C. Example 2 2-[2-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5,5-dimethyl-1,3-cyclohexanedione. (compound No. 5) To a suspension of 5.68 g (0.02 mole) of glyoxal-sodium bisulfite in 30 ml of water was added dropwise with ice-cooling 1.5 g (0.02 mole) of N-methylethylenediamine. Then to this solution was added dropwise with ice-cooling the dithiolate solution prepared in the manner shown below; To a mixture of 2.8 g (0.02 mole) of dimedone and 1.6 g (0.021 mole) of carbon disulfide in 20 ml of dimethylsulfoxide was added at room temperature 2.7 g (0.044 mole) of powdered potassium hydroxide and the mixture was stirred for 1 hour. The reaction mixture was stirred for additional one hour at room temperature. The crystalline precipitate was collected by filtration and washed with water and hexane and recrystallized from chloroform-ether to give 1.5 g of the desired product. Yield 24%; m.p. 156-157°C. Example 3 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-phenyl-1,3-cyclohexanedione. (compound No. 26) To a suspension of 3.4 g (0.01 mole) of glyoxalsodium bisulfite in 20 ml of water was added dropwise at 0°C N,N′-dimethylethylenediamine and the mixture was stirred for 1 hour. Then to this solution was added at 0°C the dithiolate solution prepared in the manner shown below; To a solution of 1.9 g (0.01 mole) of 5-phenyl-1,3-cyclohexanedione and 0.9 g (0.012 mole) of carbon disulfide in 10 ml of dimethylsulfoxide was added at 10°C 1.5 g of powdered potassium hydroxide and stirred for 1 hour. After the completion of addition, the mixture was stirred for 1 hour. The solid precipitate was collected by filtration and washed with water and then recrystallized from ethyl acetate-hexane to give 2.0 g of desired product. Yield 53%; m.p. 149-153°C. Example 4 2-[2,5-di-n-butyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-phenyl-1,3-cyclohexanedione. (Compound No. 29) The mixture of 3.4 g (0.01 mole) of glyoxalsodium bisulfite and 3.0 g (0.018 mole) of N,N′-di-n-butylethylenediamine in 30 ml of water was stirred for 1 hour at 0°C. Then to this solution was added dropwise at 0°C the dithiolate solution prepared by the reaction of 1.9 g (0.01 mole) of 5-phenylcyclohexane-1,3-dione with 0.9 g (0.012 mole) of carbon disulfide in 10 ml of dimethylsulfoxide in the presence of 1.5 g (0.027 mole) of powdered potassium hydroxide. The reaction mixture was stirred for 2 hours. Then 50 ml of water was added to the reaction solution. The crystalline precipitate was collected by filtration, washed with water and dried up and then recrystallized from ethyl acetate-n-hexane to give 1.7 g of the desired product. Yield 37%; m.p. 130-132°C. Example 5 2-[2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(4-methoxyphenyl)-1,3-cyclohexanedione. (Compound No. 53) To a suspension of 5.68 g (0.02 mole) of glyoxal-sodium bisulfite in 30 ml of water was added dropwise at room temperature 1.44 g (0.024 mole) of ethylenediamine and the mixture was stirred until it became a homogeneous solution. Then to this solution was added with ice-cooling the dithiolate solution prepared in the manner shown below; To a solution of 4.09 g (0.02 mole) of 5-(4-methoxyphenyl)-1,3-cyclohexanedione and 1.6 g (0.021 mole) of carbon disulfide in 20 ml of dimethylsulfoxide was added 2.8 g (0.05 mole) of powdered potassium hydroxide, and the mixture was stirred for one hour. The reaction mixture was stirred for additional 30 minutes at 0°C. The crystalline precipitate was collected by filtration, washed with water, and dried and recrystallized from chloroform-ether to give 1.45 g of the desired product. Yield 20%; m.p. 160-162°C. Example 6 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(2-thienyl)-1,3-cyclohexanedione. (compound No. 82) To a suspension of 2.84 g (0.01 mole) of glyoxal-sodium bisulfite in 20 ml of water was added dropwise at room temperature 1.05 g (0.01 mole) of N,N′-dimethylethylenediamine and the mixture was stirred until it became a homogeneous solution. Then to this solution was added with ice-cooling the dithiolate solution prepared in the manner mentioned below; To a solution of 1.94 g (0.01 mole) of 5-thienyl-1,3-cyclohexanedione and 0.8 g (0.01 mole) of carbon disulfide in 10 ml of dimethylformamide was added with ice-cooling 1.4 g (0.025 mole) of powdered potassium hydroxide, and the mixture was stirred for one hour. The reaction mixture was stirred for additional 30 minutes. The crystalline precipitate was collected by filtration, washed with water, dried and then recrystallized from chloroform-ether to give 1.07 g of the desired product. Yield 28%; m.p. 165-166°C. Example 7 2-[1,2,5-trimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5,5-dimethyl-1,3-cyclohexanedione. (compound No. 12) To a solution of 4.58 g (0.04 mole) of sodium bisulfite was added 3.96 g (0.02 mole) of 40% methylglyoxal and the mixture was stirred for 1 hour at room temperature. To this solution was added dropwise with ice-cooling 1.94 g (0.022 mole) of N,N′-dimethylethylenediamine and the mixture was stirred for 1 hour. Then to this solution was added with ice-cooling the dithiolate solution prepared in the manner shown below; To a mixture of 2.8 g (0.02 mole) of dimedone and 1.6 g (0.02 mole) of carbon disulfide in 15 ml of dimethylsulfoxide was added 2.7 g (0.044 mole) of powdered potassium hydroxide, and the mixture was stirred for one hour. The reaction solution was stirred for additional 20 minutes and the solid precipitate was collected by filtration. The solid was dissolved in chloroform, and the solution was washed with water and dried over anhydrous sodium sulfate. After chloroform was evaporated in vacuo, the residue was recrystallized from chloroform-ether to give 0.55 g of the desired product. Yield 8%; m.p. 161-162°C. Example 8 2-[3-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5,5-dimethyl-1,3-cyclohexanedione. (compound No. 14) To a suspension of 5.68 g (0.02 mole) of glyoxal-sodium bisulfite in 20 ml of water was added dropwise with ice-cooling 1.49 g (0.02 mole) of 1,2-propanediamine and the mixture was stirred until it became a homogeneous solution. Then to this solution was added with ice-cooling the dithiolate solution prepared in the manner shown below; To a solution of 2.8 g (0.02 mole) of dimedone and 1.6 g (0.02 mole) of carbon disulfide in 20 ml of dimethylsulfoxide was added with ice-cooling 2.7 g (0.044 mole) of powdered potassium hydroxide, and the mixture was stirred for one hour. The reaction mixture was extracted with ethyl acetate, washed three times with ice-water and dried over anhydrous magnesium sulfate. The solvent was evaporated and the residue was recrystallized from ethyl acetate-hexane to give 0.8 g of the desired product. Yield 13%; m.p. 150.0°C. Example 9 2-[2,5-acetyl-3-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5,5-dimethyl-1,3-cyclohexanedione. (compound No. 15) To a solution of 0.4 g (0.0013 mole) of 2-[3-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5,5-d methyl-1,3-cyclohexanedione in 5 ml of pyridine was added dropwise with ice-cooling 0.79 g (0.01 mole) of acetyl chloride and the mixture was stirred for 1 hour. The reaction solution was extracted with ethyl acetate, washed with 2 N hydrochloric acid and water, and then dried over magnesium sulfate. The solvent was removed and the residue was washed with ether and recrystalized from ethyl acetate-hexane to give 0.35 g of the desired product. Yield 68%; m.p. 146-150°C. Example 10 2-[2-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5,5-dimethyl-1,3-cyclohexanedione dihydrochloride salt. (compound 118) Into a solution of 1.0 g (0.0032 mole) of 2-[2-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5,5-d methyl-1,3-cyclohexanedione in 20 ml of acetone was bubbled dry hydrogen chloride with ice-cooling. After the crystalline product was precipitated, to this solution was added 20 ml of ether to further crystallize the product dissolved in acetone. The precipitate was collected by filtration and was washed with ether to give 1.1 g of the desired product. Yield 90%; m.p. 162-164°C. Now, Examples regarding pharmaceutical compositions according to this invention will be described. In the Examples, "part" is all part by weight. The kinds and the proportions of the compounding ingredients used in the composition according to this invention can be changed variously without being restricted by these Examples. Example 11 The above ingredients were mixed uniformly and made into a medicinal preparation in the form of powders or fine granules. Example 12 The above ingredients were used to be made up into powders in a similar manner to that in Example 11. Example 13 The above ingredients were uniformly mixed, kneaded, then crushed, granulated, dried and sieved to obtain granules. Example 14 A mixture of 99 parts of the granules obtained in Example 13 and 1 part of calcium stearate was compression-formed into tablets of 10 mm diameter. Example 15 The above ingredients were made up into granules in the same manner as in Example 13. Ten parts of crystalline cellulose was added to 90 parts of the granules obtained above, and the mixture was compression-molded to obtain tablets of 8 mm diameter. The tablets may be further made up into dragée by using, in appropriate amounts, a mixed suspension of syrup, gelatin and precipitated calcium carbonate, and a coloring agent. Example 16 The above ingredients were mixed with warming, then sterilized to obtain injections. Example 17 The powders obtained in Example 11 were filled into capsule containers available on the market to obtain capsules. The effect of the compound of the present invention will be illustrated by the following Test Example. Test Example 1 Effect of suppressing hepatic disorder caused by carbon tetrachloride. Test Method The test compound was dissolved or suspended in olive oil, and orally administered at a dose of 30 mg/kg to mice (6 weeks of age, dd-strain, ♂). Six hours thereafter, carbon tetrachloride was orally administered in a proportion of 0.05 ml/kg. The animals were sacrificed 24 hours after the administration of carbon tetrachloride, and the extent of liver injury was examined. On the other hand, blood was collected from the animal at the time of the sacrifice, and centrifuged to obtain plasma. The plasma glutamate pyruvate transaminase (GPT) activity was determined according to the method of Reitman-Frankel. The activity was expressed in terms of Karmen Units (K.U.). The conditions of the liver were expressed in terms of liver injury index as follows. Mice were used in groups of five and the results of test were represented by the mean value. When the GPT activity was 2,000 units or higher, or further determination was made, the activity was calculated as 2,000 units for reasons of convenience. The results obtained are shown in Table 2.

Claims: A cyclohexanedione derivative represented by the general formula (I): wherein R¹, R⁴ and R⁷ represent independently hydrogen atom or C₁ - C₈ alkyl group, R² represents hydrogen atom; C₁ - C₈ alkyl group; C₂ - C₁₆ alkenyl group; C₃ - C₈ cycloalkyl group; C₂ - C₇ alkoxycarbonyl group; C₁ - C₆ alkylthio C₁ - c₆ alkyl group; a phenyl group; a phenyl group substituted with 1 to 3 groups selected from the group consisting with 1 to 3 groups selected from the group consisting of halogen atom, C₁ - C₆ alkyl group, C₁ - C₆ haloalkyl group, C₁- C₆ alkoxy group, C₁ - C₆ alkylthio group, C₃ - C₈ cycloalkoxy group, a benzyloxy group and a benzyloxy group substituted with C₁ - C₆ alkoxy group; naphthyl group or a furyl or thienyl group, R³ represents hydrogen atom, C₁ - C₈ alkyl group or C₂ - C₇ alkoxycarbonyl group, and R⁵ and R⁶, which may be the same or different, represent hydrogen atom, C₁ - C₆ alkyl group, C₂ - C₆ alkenyl group, C₂ - C₇ alkylcarbonyl group or C₂ - C₇ haloalkylcarbonyl group and its pharmaceutically acceptable salts. A cyclohexanedione derivative or its pharmaceutically acceptable salts according to claim 1, wherein R¹, R³, R⁴, and R⁷, which may represent independently hydrogen atom or a lower alkyl group, R² represents hydrogen atom; a lower alkyl group; an alkenyl group; a cycloalkyl group; a phenyl group; a phenyl group substituted with 1 to 3 groups selected from the group consisting of halogen atom, a lower alkyl group, a lower haloalkyl group, a lower alkoxy group, a cycloalkoxy group, benzyloxy group and benzyloxy group substituted with lower alkoxy group; naphthyl group or a furyl or thienyl group, and R⁵ and R⁶, which may be the same or different, represent hydrogen atom, a lower alkyl group, a lower alkenyl group, an alkylcarbonyl group or a haloalkyl carbonyl group. A cyclohexanedione derivative or its pharmaceutically acceptable salts according to claim 1, wherein R¹, R³, R⁴, R⁵, R⁶ and R⁷ represent independently hydrogen atom or C₁ - C₄ alkyl group, and R² represents hydrogen atom; C₁ - C₄ alkyl group; a phenyl group; a phenyl group substituted with 1 to 2 groups selected from the group consisting of halogen atom, C₁ - C₄ alkyl group and C₁ - C₄ alkoxy group; or furyl group. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-1 3-cyclohexanedione. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5 5-dimethyl-1,3-cyclohexanedione. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[2-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(2-chlorophenyl)-1,3-cyclohexanedione. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(4-tolyl)-1,3-cyclohexanedione. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(4-methoxyphenyl)-1,3-cyclohexanedione. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(4-methoxyphenyl)-1,3-cyclohexanedione. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(2-furyl)-1,3-cyclohexanedione. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[1,2,5-trimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(2-furyl)-1,3-cyclohexanedione. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[1-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(4-methoxyphenyl)-1,3-cyclohexanedione. A cyclohexanedione derivative as in any one of claims 1 to 3 which is 2-[3-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nanone-8-ylidene]-5-(4-methoxyphenyl)-1,3-cyclohexanedione. A process for producing a compound represented by the general formula (I): wherein R¹, R⁴ and R⁷ represent independently hydrogen atom or C₁ - C₈ alkyl group, R² represents hydrogen atom; C₁ - C₈ alkyl group; C₂ - C₁₆ alkenyl group; C₃ - C₈ cycloalkyl group; C₂ - C₇ alkoxycarbonyl group; C₁ - C₆ alkylthio C₁ - C₆ alkyl group; a phenyl group; a phenyl group substituted with 1 to 3 groups selected from the group consisting of halogen atom, C₁ - C₆ alkyl group, C₁ - C₆ haloalkyl group, C₁ - C₆ alkoxy group, C₁ - C₆ alkylthio group, C₃ - C₈ cycloalkoxy group, a benzyloxy group and a benzyloxy group substitued with C₁ - C₆ alkoxy group; naphthyl group or a furyl or thienyl group, R³ represents hydrogen atom, C₁ - C₈ alkyl group or C₂ - C₇ alkoxycarbonyl group, and R⁵ and R⁶, which may be the same or different, represent hydrogen atom, C₁ - C₆ alkyl group, C₂ - C₆ alkenyl group, C₂ - C₇ alkylcarbonyl group or C₂ - C₇ haloalkylcarbonyl group, which comprises reacting a compound represented by the formula (II); wherein R⁴ has the same meanings as defined above, with a compound represented by the formula (III) wherein R⁵, R⁶ and R⁷ have the same meanings as defined above, and followed by a reaction with a compound represented by the formula (IV) wherein R¹, R² and R³ have the same meanings as defined above, and M represents an alkali metal atom. A pharmaceutical composition, comprising an effective amount of a cyclohexanedione derivative represented by the formula (I): (wherein R¹, R⁴ and R⁷ represent independently hydrogen atom or C₁ - C₈ alkyl group, R² represents hydrogen atom; C₁ - C₈ alkyl group; C₂ - C₁₆ alkenyl group; C₃ - C₈ cycloalkyl group; C₂ - C₇ alkoxycarbonyl group; C₁ - C₆ alkylthio C₁ - C₆ alkyl group; a phenyl group; a phenyl group substituted with 1 to 3 groups selected from the group consisting of halogen atom, C₁ - C₆ alkyl group, C₁ - C₆ haloalkyl group, C₁ - C₆ alkoxy group, C₁ - C₆ alkylthio group, C₃ - C₈ cycloalkoxy group, a benzyloxy group and a benzyloxy group substituted with C₁ - C₆ alkoxy group; naphthyl group or a furyl or thienyl group, R³ represents hydrogen atom, C₁ - C₈ alkyl group or C₂ - C₇ alkoxycarbonyl group, and R⁵ and R⁶, which may be the same or different, represent hydrogen atom, C₁ - C₆ alkyl group, C₂ - C₆ alkenyl group, C₂ - C₇ alkylcarbonyl group or C₂ - C₇ haloalkylcarbonyl group) and or its pharmaceutically acceptable salts, and a pharmaceutical carrier. A pharmaceutical composition according to claim 15, wherein R¹, R³, R⁴ and R⁷ represent independently hydrogen atom or a lower alkyl group, R² represets hydrogen atom; a lower alkyl group; an alkenyl group; a cycloalkyl group; a phenyl group; a phenyl group substituted with 1 to 3 groups selected from the group consisting of halogen atom, a lower alkyl group, a lower haloalkyl group, a lower alkoxy group, a cycloalkoxy group, a benzyloxy group and a benzyloxy group substituted with lower alkoxy group; naphthyl group or a furyl or thienyl group, and R⁵ and R⁶, which may be the same or different, represent hydrogen atom, a lower alkyl group, a lower alkenyl group, an alkylcarbonyl group or a haloalkyl carbonyl group. A pharmaceutical composition according to claim 15, wherein R¹, R³, R⁴, R⁵, R⁶ and R⁷ represent independently hydrogen atom or C₁ - C₄ alkyl group, and R² represents hydrogen atom; C₁ - C₄ alkyl group; a phenyl group; a phenyl group substituted with 1 to 2 groups selected from the group consisting of halogen atom, C₁ - C₄ alkyl group and C₁ - C₄ alkoxy group; or furyl group. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-1 3-cyclohexanedione. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5 5-dimethyl-1,3-cyclohexanedione. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[2-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(2-chlorophenyl)-1,3-cyclohexanedione. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5 (4-tolyl)-1,3-cyclohexanedione. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5 (4-methoxyphenyl)-1,3-cyclohexanedione. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(4-methoxyphenyl) -1,3-cyclohexanedione. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[2,5-dimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5 2-furyl)-1,3-cyclohexanedione. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[1,2,5-trimethyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene -5-(2-furyl)-1,3-cyclohexanedione. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[1-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(4-methoxyphenyl)-1,3-cyclohexanedione. A pharmaceutical composition as in any one of claims 15 to 17, in which said cyclohexanedione derivative is 2-[3-methyl-2,5-diaza-7,9-dithiabicyclo-(4,3,0)-nonane-8-ylidene]-5-(4-methoxyphenyl)-1,3-cyclohexanedione.

Inventors: HIRAGA, KUNIKAZU, KUBOTA, SHUHEI, NAKAYAMA, KEISUKE, UCHIDA, MATAZAEMON
Applicants: NIHON NOHYAKU CO., LTD.
Application year: 1987
Main classification: C07D495
IPC codes: A61K31, A61P1, C07D495