A PROCESS FOR PREPARING 2-AMINOMALONIC ACID DERIVATIVES

Abstract: A process for preparing 2-amino malonic acid derivatives of formula (1): wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, R 2 and R 3 are the same or different, and are lower alkyl or aralkyl, and R 4 is a protecting group, which process comprises the steps of reducing a compound of formula (6): wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, R 2 and R 3 are the same or different, and are lower alkyl or aralkyl, and R 4 is a protecting group.

Description: The present invention relates to a process for preparing 2-amino malonic acid derivatives which are used for preparing 2-amino-1,3-propanediol derivatives having excellent pharmacological activity, in particular immune suppression activity, rejection suppression activity, and prevention and therapy of autoimmune diseases. Japanese Patent No. 2579602 (U.S. Patent No. 5,604,229) discloses 2-amino-1,3-propanediol derivatives, and their properties such as pharmacological activity. The patent discloses a process for preparing 2-amino-1,3-propanediol derivatives. However, the process has disadvantages in that it contains many complicated steps, and it produces intermediates as oily substances or various isomeric mixtures. Accordingly, it is necessary to isolate and purify the intermediate products by conventional methods such silica gel chromatography which accompany with complicated operation and use of large quantity of organic solvent. For that reason, it is difficult to remove undesired isomers, homologues, and other impurities. Thus, there is a need to a process which makes it possible to prepare an intended product with high purity, in high yield, without complicated steps, and in a large scale. That is, there is a need to a process which makes it possible to prepare 2-amino malonic acid derivatives as intermediates of 2-amino-1,3-propandiol derivatives easily in a high yield. Accordingly, an object of the present invention is to provide a process for preparing 2-amino malonic acid derivatives which permits the production thereof in a high yield readily. After intensive investigations, the inventors have found that the above-described object of the present invention can be attained by preparing and 2-amino malonic acid derivatives via a specific synthetic route. The present invention has been completed on the basis of the above-described finding. The present invention provides a process for preparing 2-amino malonic acid derivatives of formula (1): wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, R 2 and R 3 are the same or different, and are lower alkyl or aralkyl, and R 4 is a protecting group, which process comprises the step of reducing a compound of formula (6). wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, R 2 and R 3 are the same or different, and are lower alkyl or aralkyl, and R 4 is a protecting group in the presence of a palladium or nickel catalyst. As used herein, the term "lower alkyl" refers to a group selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tertiary butyl. The compound of the formula (6), is obtainable according to a process which comprises the step of reacting a compound of formula (7): wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, and Z is a leaving group, and 2-(N-substituted) amino malonic diester of formula (3): wherein R 2 and R 3 are the same or different, and are lower alkyl or aralkyl, and R 4 is a protecting group. Figure 1 shows the synthetic route of the process for preparing 2-amino malonic acid derivatives of the present invention. First, the detailed description will be made on the process for preparing 2-amino malonic acid derivatives of formula (1), refering to Figure 1. wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, R 2 and R 3 are the same or different, and are lower alkyl or aralkyl, and R 4 is a protecting group. A process for preparing 2-amino malonic acid derivatives may comprise the following synthetic route, as shown in Figure 1. The detailed description will be made on the step A. In the step A , the compound of formula (9) is prepared by reacting the compound of formula (10) and the compound of formula (11). In the formula (10), A is linear or branched chain alkylene having from 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms, such as methylene, ethylene and propylene. Ethylene is most preferred. R 5 is an acyl type protecting group, such as acetyl, benzoyl, trichloroacetyl and pivaloyl. Acetyl is most preferred. In the formula (11), R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, preferably 6 to 8 carbon atoms, such as n-hexyl, n-heptyl and n-octyl with n-heptyl being most preferred. X is halogen, such as chlorine, bromine and iodine with chlorine being most preferred. In the formula (9), A and R 5 are the same as defined in the formula (10), and R 1 is the same as defined in the formula (11). A method for reacting the compound of the formula (10) and the compound of the formula (11) is not particularly limited, and it can be carried out by well-known methods. The methods include, for example, Friedel-Crafts reaction wherein the compound of the formula (10) is reacted with the compound of the formula (11) in the presence of Lewis acid, such as anhydrous aluminum trichloride, anhydrous aluminum tribromide, anhydrous zinc chloride, anhydrous ferric chloride, anhydrous titanium tetrachloride, boron trifluoride or anhydrous tin chloride. Any solvents which are inactive in the reaction may be used. Examples of such solvents include 1,2-dichloroethane, dichloromethane, chloroform, tetrachloromethane, nitrobenzene and carbon disulfide. A reaction temperature ranges from -78 to 90 °C. A reaction time varies depending on the reaction conditions, but it usually ranges from 30 minutes to 2 days. In the method, the compound of the formula (10) is preferably dissolved in the solvent in the content ranging from 1 to 70 % by weight, the catalyst is preferably used in the amount of 1 to 5 moles per 1 mole of the compound of the formula (10). The compound of the formula (9) obtained by the above-mentioned step can be purified by well-known method in the field of organic chemistry, such as recrystallization, chromatography, distillation, extraction by the solvent and ion exchange process. Next, the detailed description will be made on the step B. In the step B, the compound of formula (5) is prepared by deacylating the compound of the formula (9). In the formula (5), A is the same as defined in the formula (10), and R 1 is the same as defined in the formula (11). A method for deacylating the compound of the formula (9) is not particularly limited, and it can be carried out by well-known methods which include, for example, the method for ester exchange or hydrolysis of the compound of the formula (9) with a base such as sodium methylate, sodium ethylate, sodium hydroxide, potassium hydroxide and lithium hydroxide, or an acid such as hydrochloric acid and sulfuric acid. Any of known solvents which are inactive in the reaction may be used, for example, methanol, ethanol, isopropyl alcohol, tetrahydrofuran, dioxane, water, and mixture thereof. A reaction temperature ranges from -25°C to boiling point of the solvent. A reaction time varies depending on the reaction conditions, but it usually ranges from 30 minutes to 2 days. In the method, the compound of the formula (9) is preferably dissolved in the solvent in the content ranging from 1 to 70 % by weight, and the base or the acid is preferably used in the amount of 0.01 to 2 moles per 1 mole of the compound of the formula (9). The compound of the formula (5) obtained by the above-mentioned step can be purified by well-known method in the field of organic chemistry, such as recrystallization, chromatography, distillation, extraction by the solvent and ion exchange process. Next, the detailed description will be made on the step D. In the step D, the compound of formula (7) is prepared by converting hydroxyl group of the compound of the formula (5) to a leaving group. In the formula (7), A is the same as defined in the formula (10), R 1 is the same as defined in the formula (11), and Z is a leaving group. Z includes, for example, halogen such as chlorine, bromine, iodine, p-toluene sulfonyloxy, methane sulfonyloxy, and trifluoromethane sulfonyloxy. A method for converting the hydroxyl group of the compound of the formula (5) to a leaving group is not particularly limited, and it can be carried out by well-known methods which include, for example, the method for halogenation of the compound of the formula (5) by using thionyl chloride, thionyl bromide, hydrogen chloride, hydrogen bromide, phosphorus trichloride, phosphorus tribromide, phosphorus pentachloride, phosphorus pentabromide, chlorine, bromine, iodine, tetrachloromethane. tetrabromomethane, N-chloro succinic imide, N-bromo succinic imide, sodium chloride, sodium bromide or sodium iodide, and the method for converting the compound of the formula (5) to a sulfonate by using p-toluenesulfonyl chloride, methanesulfonyl chloride, trifluoromethanesulfonyl chloride, anhydrous p-toluenesulfonic acid, anhydrous methanesulfonic acid or anhydrous trifluoromethanesulfonic acid. In the step D, two-step reaction: conversion of the compound of the formula (5) to a sulfonate; and halogenation of the sulfonate by using sodium chloride, sodium bromide or sodium iodine may be carried out. Any solvents which are inactive in the reaction may be used, for example, ethyl acetate, benzene, toluene, dichloroethane, 1,2-dichloroethane, pyridine, N,N-dimethylformamide, diethyl ether, tetrachloromethane, chloroform, acetonitrile, 2-butanone, acetone and the mixture thereof. In the reaction, the auxiliary such as pyridine, triethylamine, imidazole, dimethylaminopyridine, triphenylphosphine, triphenyl phosphonate, sulfuric acid and the mixture thereof preferably may be used. A reaction temperature ranges from -25°C to boiling point of the solvent. A reaction time varies depending on the reaction conditions, but it usually ranges from 30 minutes to 2 days. In the method, the compound of the formula (5) is preferably dissolved in the solvent in the content ranging from 1 to 70 % by weight, reagent for halogenation or reagent for sulfonylation is preferably used in the amount of 1 to 50 moles per 1 mole of the compound of the formula (5). The compound of the formula (7) obtained by the above-mentioned step can be purified by well-known method in the field of organic chemistry, such as recrystallization, chromatography, distillation, extraction by the solvent and ion exchange process. Next, the detailed description will be made on the step J. In the step J, the compound of the formula (6) is prepared by reacting the compound of the formula (7) and 2-(N-substituted) aminomalonic diester of the formula (3). In the formula (3), R 2 and R 3 are the same or different, and are lower alkyl or aralkyl. The lower alkyl is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tertiary butyl. The aralkyl includes, for example, benzyl, nitrobenzyl, methoxybenzyl and methylbenzyl. Ethyl is preferred. R 4 is a protecting group which is used in the field of synthetic organic chemistry, and includes, for example, acetyl, benzoyl, tertiary butoxycarbonyl and benzyloxycarbonyl. Acetyl is preferred. In the formula (6), A is the same as defined in the formula (10), R 1 is the same as defined in the formula (11), and R 2 , R 3 and R 4 are the same as defined in the formula (3). A method for preparing the compound of the formula (6) by reacting the compound of the formula (7) and the 2-(N-substituted) aminomalonic diester is not particularly limited, and it can be carried out by well-known methods which include, for example, the method for condensation of the compound of the formula (7) and the 2-(N-substituted) aminomalonic diester of the formula (3) in the presence of a base such as sodium ethylate, sodium hydride, sodium methylate and sodium. Any known solvents which are inactive in the reaction may be used, for example, ethanol, methanol, tetrahydrofuran, N,N-dimethylformamide, toluene, dimethyl sulfoxide and the mixture thereof. A reaction temperature ranges from -20°C to boiling point of the solvent. A reaction time varies depending on the reaction conditions, but it usually ranges from 30 minutes to 2 days. In the method, the compound of the formula (7) is preferably dissolved in the solvent in the content ranging from 1 to 70 % by weight, 2-(N-substituted) aminomalonic diester of the formula (3) and the base are preferably used in the amount of 1 to 10 moles per 1 mole of the compound of the formula (7). The compound of the formula (6) obtained by the above-mentioned step can be purified by well-known method in the field of organic chemistry, such as recrystallization, chromatography, distillation, extraction by the solvent and ion exchange process. By the way, in the step J, the compound of the formula (21) is produced as by-product. The compound of the formula (6) can be obtained by reacting the compound of the formula (21) and the 2-(N-substituted) aminomalonic diester of the formula (3) under the same reaction conditions of the above-mentioned step. In the formula (21), R 1 is the same as defined in the formula (11). Next, the detailed description will be made on the step K. In the step K, the compound of the formula (1) is prepared by reducing ketone group of the compound of the formula (6) to methylene group. A method for reducing the ketone group of the compound of formula (6) to methylene group in the presence of a palladium or nickel catalyst is not particularly limited, and it can be carried out by well-known method which include, for example, the method for hydrocracking the compound of formula (6) by hydrogen or sodium borohydride in the presence of palladium catalyst (palladium carbon, palladium, palladium barium sulfate, palladium chloride and the like) or nickel catalyst (Raney Nickel, nickel acetate and the like). Any known solvents which are inactive in the reaction may be used. Ethanol, methanol, ethyl acetate, dioxane, water and the mixture thereof are preferred. It is possible to promote a reaction by adding an acid such as hydrochloric acid and acetic acid, or by applying a pressure. A reaction temperature ranges from -25°C to boiling point of the solvent. A reaction time varies depending on the reaction conditions, but it usually ranges from 30 minutes to 20 days. In the method, the compound of formula (6) is preferably dissolved in the solvent in the content ranging from 1 to 70 % by weight, and the catalyst is preferably used in the amount of 0.001 to 20g per 1g of the compound of formula (6). The compound of the formula (1) obtained by the above-mentioned step can be purified by well-known method in the field of organic chemistry, such as recrystallization, chromatography, distillation, extraction by the solvent and ion exchange process. Next, the detailed description will be made on the step N. In the step N, the compound of the formula (7) is prepared by reacting the compound of the formula (15) and the compound of the formula (11). In the formula (15), A is the same as defined in the formula (10), and Z is the same as defined in the formula (7). A method for preparing the compound of the formula (7) by reacting the compound of the formula (15) and the compound of the formula (11) is not particularly limited, and it can be carried out by well-known method which include, for example, a method similar to the step A. Next, the detailed description will be made on the compound of the formula (5), the compound of the formula (7) and the compound of the formula (6) used in the present invention. The compound of the formula (5) is an intermediate which is optionally used for preparing 2-amino malonic acid derivatives according to the process of the present invention, and has the following formula: wherein A and R 1 are the same as defined in the formula (1). Amethod for preparing the compound of the formula (5) optionally used in the present invention is not particularly limited. For example, it can be prepared by deacylating the compound of the formula (9) as described in the process for preparing 2-amino malonic acid derivatives of the present invention. The compound of the formula (5) is obtained in the form of crystal. Accordingly, it can be purified readily, and it is useful as an intermediates for preparing 2-amino malonic acid derivatives which are intermediates for preparing 2-amino-1,3-propanediol derivatives. Next, the detailed description will be made on the compound of the formula (7). The compound of the formula (7) is an intermediate which is optionally used for preparing the 2-amino malonic acid derivatives in the process of the present invention, and has the following formula: wherein A and R 1 are the same as defined in the formula (1), and Z is a leaving group. A method for preparing the compound of the formula (7) of the present invention is not particularly limited. For example, it can be prepared by converting hydroxyl group of the compound of the formula (5) to a leaving group, as explained above for the production of 2-amino malonic acid derivatives. The compound of the formula (7) is obtained in the form of crystal. Accordingly, it can be purified readily, and it is useful for an intermediate for preparing 2-amino masonic acid derivatives which are intermediates for preparing 2-amino-1,3-propanediol derivatives. Next, the detailed description will be made on the compound of the formula (6). The compound of the formula (6) is an intermediate which is used for preparing 2-amino malonic acid derivatives in the process of the present invention, and has the following formula: wherein A, R 1 , R 2 , R 3 and R 4 are the same as defined in the formula (1). A method for preparing the compound of the formula (6) used in the present invention is not particularly limited. For example, it can be prepared by reacting the compound of the formula (4) and 2-(N-substituted) amino malonic diester of the formula (5). The compound of the formula (6) is obtained in the form of crystal. Accordingly, it can be purified readily, and it is useful for an intermediate for preparing 2-amino malonic acid derivatives which are intermediates for preparing 2-amino-1,3-propanediol derivatives. The following Examples will further illustrate the present invention, which by no means limit the present invention. Example 1 Step A: Preparation of 2-(4-octanoyl phenyl) ethyl acetate (9) Octanoyl chloride (216 g) and phenetyl acetate (285 g) were dissolved in 1,2-dichloroethane to obtain a solution. Then aluminum chloride (372g) was added to the solution with cooling little by little. After adding aluminum chloride, the solution was stirred at room temperature for 2 hours. The solution was stirred for further 30 minutes, and then was poured into ice water. Dichloroethane layer was taken, washed with water, dried over anhydrous magnesium sulfate, and concentrated. The residue was distilled under vacuum to obtain a fraction which contains 2-(4-octanoyl phenyl) ethyl acetate as a major component (280 g). TLC Rf: 0.3 (hexane/ethyl acetate = 5/1, silica gel 60F 254 plate) EIMS m/z: 230 (M- CH 3 COOH) + , 191, 159, 146, 131 Step B: Preparation of 4'-(2-hydroxy ethyl) octanophenone (5) A solution (18.8 ml) of 28 % sodium methylate in methanol was added to a solution of the material (280 g) which contains 2-(4-octanoyl phenyl) ethyl acetate obtained in the step A as a major component in methanol (200 ml), and the solution was stirred at room temperature for 1 hour. Suspension of Amberlite IR-120B in methanol (98 ml) was added to the solution, and the mixture was filtered. The filtrate was concentrated, and the residue was recrystallized from hexane-ethyl acetate (10:1) to obtain 4'-(2-hydroxy ethyl) octanophenone (138 g) in the form of colorless crystal. TLC Rf: 0.4 (hexane/ethyl acetate = 2/1, silica gel 60F 254 plate) melting point: 47.4°C IR (KBr) 3260, 2910, 2850, 1680 cm -1 UVλ max (MeOH) nm (ε) : 216.4 (3047), 261.2 (4421) 1 H-NMR (500 MHz, CDCl 3 )δ: 7.91 (2H, d, J = 8.3 Hz, C 6 -H 2 ), 7.32(2H,d, J = 8.5 Hz, C 6 -H 2 ), 3.90 (2H, t, J =6.6 Hz, CH 2 OH), 2.94 (2H, t, J = 7.3 Hz, COCH 2 ), 2.93 (2H, t, J = 6.6 Hz, Ph-CH 2 ), 1.72 (2H, qui, J = 7.3 Hz, CH 2 ), 1.59 (1H, br s, OH), 1.40 ∼ 1.26 (8H, m, CH 2 ×4), 0.88 (3H, t, J =7.1 Hz, CH 3 ). EIMS m/z: 248 (M) + , 230, 203, 177, 164, 149 Step D-1: Preparation of 2-(4-octanoyl phenyl) ethyl p-toluene sulfonate (7) 4'-(2-Hydroxy ethyl) octanophenone (1.0 g) prepared in the step B was dissolved in dichloromethane (10 ml) to obtain a solution. p-Toluene sulfonyl chloride (923 mg) and pyridine (383 mg) were added to the solution with cooling, and the mixture was stirred at room temperature for 2 hours. After the reaction, ice water was added to the solution, the solution was stirred at room temperature for 20 minutes. Dichloromethane layer was washed with 2% hydrochloric acid, sodium bicarbonate solution, and water. The dichloromethane layer was dried over anhydrous sodium sulfate, and concentrated. The residue was recrystallized from hexane-ethyl acetate (10:1) to obtain 2-(4-octanoyl phenyl) ethyl p-toluene sulfonate (950 mg) in the form of colorless crystal. TLC Rf: 0.4 (hexane/ethyl acetate = 3/1, silica gel 60F 254 plate) melting point: 59∼60°C IR (KBr) 2960, 2850, 1680, 1360, 1170, 960, 920, 810, 660, 550 cm -1 1 H-NMR (500 MHz, CDCl 3 ) δ: 7.83(2H, d, J = 8.3 Hz, C 6 -H 2 ), 7.67(2H, d, J = 8.3Hz, C 6 -H 2 ), 7.26(2H, d, J=8.5Hz, C 6 -H 2 ), 7.19(2H, d, J=8.5Hz. C 6 -H 2 ), 4.24(2H. t, J=6.8Hz, TsOCH 2 ), 3.00(2H, t, J=6.8Hz, Ph-CH 2 ), 2.92(2H,t, J=7.3Hz, COCH 2 ), 2.42(3H, s, Ph-CH 3 ), 1.72(2H,qui, J=7.3Hz, CH 2 ), 1.40∼1.26 (8H, m, CH 2 X4), 0.88(3H, t,J=7.1Hz, CH 3 ) EIMS m/z: 303 (M-(CH 2 ) 6 CH 3 ) + , 230, 146, 131, 91 Step D-2: Preparation of 4'-(2-iodoethyl) octanophenone (7) 2-(4-Octanoyl phenyl) ethyl p-toluene sulfonate (1.23 g) prepared in the above-described procedure was dissolved in 2-butanone (18 ml) to obtain a solution. Sodium iodide (550 mg) was added to the solution, and the solution was heated to reflux for 40 minutes. The reaction solution was concentrated, and the solution was partitioned with water-dichloromethane. The dichloromethane layer was washed with water, dried over anhydrous sodium sulfate, and concentrated to obtain 4'-(2-iodoethyl) octanophenone (1.09 g) in the form of white crystal. TLC Rf: 0.3 (Hexane / EtOAc = 20 / 1, silica gel 60F 254 plate) melting point: 36.5°C IR (KBr) 2950, 2920, 2850, 1680, 1600, 1230 cm UVλ max (MeOH) nm (ε): 215.8 (4371), 256.2 (6356). 1 H-NMR (500 MHz, CDCl 3 ) δ: 7.90 (2H, d, J = 8.3 Hz, C 6 -H 2 ), 7.26 (2H, d, J = 8.1 Hz, C 6 -H 2 ), 3.35 (2H, t, J = 7.3Hz, CH 2 ), 3.22 (2H, t, J = 7.6 Hz, CH 2 ), 2.92(2H, t, J = 7.6 Hz, COCH 2 ), 1.71 (2H, qui, J= 7.1 Hz, CH 2 ), 1.36∼1.25 (8H, m, CH 2 ×4), 0.86 (3H, t, J = 6.8 Hz, CH 3 ) EIMS m/z: 274 (M- CH=CH(CH 2 ) 3 CH 3 ) + , 259, 203, 147. Step D-3: Preparation of 4'-(2-iodoethyl) octanophenone (7) 4'-(2-Hydroxy ethyl) octanophenone prepared in the step B (137 g), imidazole (53 g) and triphenyl phosphine (174 g) were dissolved in ethyl acetate (550 ml) to obtain a solution. Iodine (197 g) was added to the solution with cooling, and the solution was stirred at room temperature for 1 hour. Then the reaction solution was diluted with ethyl acetate, the solution was washed with saturated sodium sulfite solution, and saturated saline solution, dried over anhydrous magnesium sulfate, and concentrated. The concentrated residue was extracted with hexane-ethyl acetate (20:1), and extracted solution was passed through a silica gel layer. The filtrate was concentrated to obtain 4'-(2-iodoethyl) octanophenone (175 g) in the form of white crystal. Step J-1: Preparation of diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate (6) 4'-(2-Iodoethyl) octanophenone (175 g) prepared in the step D-3 was dissolved in anhydrous tetrahydrofuran (700 ml) to obtain 4'-(2-iodoethyl) octanophenone solution. Diethyl acetamide malonate (320 g) and sodium ethylate (100 g) was dissolved in anhydrous ethanol (1050 ml), and the 4'-(2-iodoethyl) octanophenone (175 g) solution was added, and the solution was heated to reflux for 7 hours. Tetrahydrofuran was removed by distillation from the solution. The solution was poured into ice water to obtain a precipitate which was recrystallized from hexane-ethyl acetate (40:1) to obtain diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate (110 g) in the form of colorless crystal. TLC Rf: 0.5 (hexane/ethyl acetate =1/1, silica gel 60F 254 plate) melting point: 79.0°C IR (KBr) 3250, 2930, 2850, 1750, 1680, 1650, 1520, 1260, 1220, 1200 cm -1 UVλ max (MeOH) nm (ε): 216.7 (5487), 256.7 (7810) 1 H-NMR (500 MHz, CDCl 3 ) δ: 7.84 (2H, d, J = 8.3 Hz, C 6 -H 2 ), 7.21 (2H, d, J = 8.1 Hz, C 6 -H 2 ), 6.75 (1H, br s, NH), 4.20 (2H, q,J=6.8 Hz,O CH 2 CH 3 ), 4.19 (2H,q,J=7.1 Hz, O CH 2 CH 3 ), 2.90 (2H, t, J = 7.3 Hz, COCH 2 ), 2.69 (2H, m, Ph·CH 2 ), 2.51 (2H, m, CH 2 ), 1.96 (3H, s, Ac), 1.69 (2H, qui, J = 7.3 Hz, CH 2 ), 1.32 (2H, m, CH 2 ), 1.27 (6H, m, CH 2 ×3), 1.23(6H,t,J=7.1Hz, OCH 2 CH 3 ×2), 0.86 (3H, J = 6.8 Hz, CH 3 ) EIMS m/z: 402 (M-OCH 2 CH 3 ) + , 332, 231, 217, 171, 131 Step J-2: Preparation of diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate (6) 4'-(2-Iodoethyl) octanophenone prepared (5 g) in the step D-3 was dissolved in anhydrous N,N-dimethylformamide (15 ml) to obtain 4'-(2-iodoethyl) octanophenone solution. Diethyl acetamide malonate (9.09 g) was dissolved in anhydrous N,N-dimethylformamide (30 ml) to obtain a solution to which 60 % sodium hydride oil dispersion (1.23 g) was added with cooling. The solution was stirred under atmosphere of nitrogen for 1 hour. 4'-(2-Iodoethyl) octanophenone solution was added to the solution, and the solution was stirred under atmosphere of nitrogen at 60 °C for 2 hours. The reaction solution was poured into ice water, and extracted with ether, and washed with saturated saline solution. The extracted solution was dried over anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography using hexane-ethyl acetate (1:0→3:1) as an eluate to obtain diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate (3.2 g) and 4'-vinyl octanophenone (1.5 g) in the form of colorless crystal, respectively. The diethyl acetamide malonate (4.25 g) was dissolved in anhydrous N,N-dimethylformamide (30 ml) to obtain a solution, to which 60 % sodium hydride oil dispersion (574 mg) was added. The solution was stirred under atmosphere of nitrogen at room temperature for 30 minutes. 4'-Vinyl octanophenone (1.5 g) and anhydrous ethanol (7.5 ml) were added to the solution, and the solution was stirred under atmosphere of nitrogen at 60°C for 6 hours, and the solution was stirred at room temperature for 2 days. The reaction solution was poured into ice water, extracted with ether, and washed with saturated saline solution. The extracted solution was dried over anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography using hexane-ethyl acetate (1:0→4:1) as an eluate to obtain diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate (2.29 g) in the form of colorless crystal. 4'-vinyl octanophenone: TLC Rf: 0.4 (hexane/ethyl acetate = 20:1, silica gel 60F 254 plate) IR (KBr) 2920, 2850, 1670, 1470, 1410, 1320, 1280, 990, 910, 860 cm -1 1 H-NMR (400 MHz, CDCl 3 ) δ: 7.92 (2H, d, J = 8.3 Hz, C 6 -H 2 ), 7.47 (2H, d, J=8,3 Hz, C 6 -H 2 ), 6.75(1H, dd, J=17.6 and 10.9Hz, CH=), 5.86(1H, d, J=17.7Hz, CHa=), 5.38 (1H, d, J=10.9Hz, CHb=), 2.94 (2H, t, J=7.3Hz, COCH 2 ), 1.73 (2H, qui, J= 7.3Hz, CH 2 ), 1.35 ∼ 1.29(8H, m, CH 2 × 4), 0.88(3H, t, J=6.8Hz, CH 3 ) 13 C-NMR(400 MHz, CDCl 3 ) δ:200.1, 141.9, 136.3, 136.0, 128.7, 128.5 126.3, 116.5, 38.7, 31.7, 29.4, 29.2, 24.5, 22.6, 14.1 EIMS m/z: 230 (M) + , 159, 146, 131, 103, 77 Step J-3: Preparation of diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate (6) 2-(4-Octanoyl phenyl) ethyl p-toluene sulfonate prepared in the step D-1 (500 mg), diethyl acetamide malonate (810 mg) and sodium ethylate (313 mg) were dissolved in anhydrous ethanol (1.5 ml) - anhydrous N,N-dimethylformamide (6 ml) to obtain a solution. The solution was stirred under atmosphere of nitrogen at 60°C overnight. The reaction solution was poured into ice water, extracted with ether, and washed with saturated saline solution. The extracted solution was dried over anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography using hexane-ethyl acetate (1:0→3:1) as an eluate to obtain diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate (417 mg) in the form of colorless crystal. Step K: Preparation of diethyl acetamide-2-(4-octyl phenyl) ethyl malonate (1) Diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate prepared in the step J (923 g) was stirred in ethanol (10 L) under atmosphere of hydrogen in the presence of 5 % palladium carbon (138 g) overnight. The catalyst was removed by filtration, and the filtrate was concentrated. The residue was recrystallized from hexane to obtain diethyl acetamide-2(4-octyl phenyl) ethyl malonate (670 g) in the form of colorless crystal. TLC Rf: 0.6(hexane/ethyl acetate = 1/1, silica gel 60F 254 plate) melting point: 61.0°C IR (KBr) 3300, 2920, 2850, 1750, 1650, 1520, 1220, 1200 cm -1 UVλ max (MeOH) nm (ε):219.1(5017), 259.2 (303.5), 264.5 (392.4), 272.7(357.7) 1 H-NMR (270 MHz, DMSO-d 6 ) δ: 8.32(1H, brs, NH), 7.08(2H, d, J=7.9Hz, C 6 -H 2 ), 7.02(2H, d, J=7.9Hz, C 6 -H 2 ), 4.13 (4H, q, J= 7.3Hz, OCH 2 CH 3 X2), 2.52(4H, m, PH-CH 2 X 2 ), 2.37(2H, m, CH 2 ), 1.94(3H, s, Ac), 1.52(2H, m, CH 2 ), 1.24(10H, m, CH 2 X5), 1.15 (6H, t, J=7.3Hz, OCH 2 CH 3 X2), 0.85(3H, t, J=6.6Hz, CH 3 ) EIMS m/z: 388 (M-OCH 2 CH 3 ) + , 318, 301, 244, 217, 171, 143 Step N: Preparation of 4'-(2-iodo ethyl) octanophenone (7) (2-Bromoethyl) benzene (5.0 g) and octanoyl chloride (4.83 g) were dissolved in dichloromethane (40 ml) to obtain a solution. Aluminum chloride (3.67 g) was added to the solution at - 20°C, and the solution was stirred at - 20°C for 1 hour, and at room temperature overnight. The reaction solution was added to ice water, and extracted with ether. The extracted solution was washed with 1N hydrochloric acid, saturated saline solution, saturated sodium bicarbonate and saturated saline solution. Obtained ether layer was dried over anhydrous magnesium sulfate, and concentrated. The concentrated residue was subjected to silica gel column chromatography using hexane-ethyl acetate (80:1→20:1) as an eluate to obtain a fraction which contains 4'-(2-bromoethyl) octanophenone as a major component (6.96 g) in the form of oily substance. TLC Rf: 0.3 (hexane/ethyl acetate = 20:1, silica gel 60F 254 plate) IR (CCl 4 ) 2960, 2930, 2860, 1690, 1610, 1410, 1260, 1220, 1180 cm -1 1 H-NMR (500MHz. CDCl 3 )δ: 7.92(2H, d, J=8.3Hz, C 6 -H 2 ), 7.30 (2H, d, J=8,3Hz, C 6 -H 2 ), 3,59(2H, t, J=7.4Hz, BrCH 2 ), 3.22(2H, t, J=7.4Hz, Ph-CH 2 ), 2.94(2H, t, J= 7.4Hz, Ph-CH 2 ), 1.73(2H, qui, J=7.4Hz,CH 2 ), 1.38 ∼ 1.27(8H, CH 2 X4), 0.88(3H, t, J=7.1Hz,CH 3 ) EIMS m/z: 312 and 310 (M) + , 228 and 226, 213 and 211, 203, 133, 104 Step J-4: Preparation of diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate (6) The fraction which contains 4'-(2-iodoethyl) octanophenone prepared in the step N (500 mg) was dissolved in anhydrous ethanol (2 ml) to obtain a solution. Sodium ethylate (164 mg) was added to the solution. The mixture was stirred under atmosphere of nitrogen at 60°C for 1 hour. The suspension was dissolved in N,N-dimethylformamide (10 ml) to obtain a solution. Diethyl acetamide malonate (1050 mg) and sodium ethylate (245 mg) were added to the solution, and the solution was stirred under atmosphere of nitrogen at 60°C overnight. The reaction solution was poured into ice water, extracted with ether, and washed with saturated saline solution. The extracted solution was dried over anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography using hexane-ethyl acetate (1:0→3:1) as an eluate to obtain diethyl acetamide-2-(4-octanoyl phenyl) ethyl malonate (477 mg) in the form of colorless crystal. The method for preparing 2-amino malonic acid derivatives according to the present invention permits the production of a compound which is useful as an intermediate for preparing 2-amino-1,3-propanediol derivatives.

Claims: A process for preparing 2-amino malonic acid derivatives of formula (1): wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, R 2 and R 3 are the same or different, and are selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tertiary butyl or aralkyl, and R 4 is a protecting group, which process comprises the step of reducing a compound of formula (6): wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, R 2 and R 3 are the same or different, and are selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tertiary butyl or aralkyl, and R 4 is a protecting group in the presence of a palladium or nickel catalyst. A process according to claim 1, wherein the compound of the formula (6), is prepared via a process comprising the step of reacting a compound of the formula (7): wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, and Z is a leaving group, and 2-(N-substituted) amino malonic acid diester of the formula (3): wherein R 2 and R 3 are the same or different, and are selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tertiary butyl or aralkyl, and R 4 is a protecting group. The process according to claim 1 or 2, wherein the compound of the formula (7) is prepared by converting hydroxyl group of the compound of formula (5) to a leaving group: wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, and R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms. The process according to claim 3, wherein the compound of the formula (5) is prepared by deacylating of the compound of the formula (9): wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, and R 5 is an acyl type protecting group. The process according to claim 1 or 2, wherein the compound of the formula (7) is prepared by reacting the compound of the formula (11): wherein R 1 is linear or branched chain alkyl having from 2 to 20 carbon atoms, and X is halogen, and the compound of formula (15): wherein A is linear or branched chain alkylene having from 1 to 10 carbon atoms, and Z is a leaving group. The process according to claim 1 or 2, wherein R 2 and R 3 are ethyl groups. The process according to claim 1, 2 or 4, wherein R 4 and R 5 are acetyl groups. The process according to claim 1 or 2, wherein R 1 is n-heptyl group. The process according to claim 1 or 2, wherein A is ethylene group. The process according to claim 2, wherein Z is iodine, bromine or p-toluene sulfonyloxy.

Inventors: FUJITA TETSURO, HIRASE SUSUMU, HIROSE RYOJI, SASAKI SHIGEO, YONETA MASAHIKO, FUJITA, TETSURO, HIRASE, SUSUMU, HIROSE, RYOJI, SASAKI, SHIGEO, YONETA, MASAHIKO, HIRASE, Susumu, Taito Co., Ltd, HIROSE, Ryoji, Taito Co., Ltd, SASAKI, Shigeo, Taito Co., Ltd, YONETA, Masahiko, Taito Co., Ltd
Applicants: MITSUBISHI PHARMA CORP, TAITO CO, MITSUBISHI PHARMA CORPORATION, TAITO CO., LTD.
Application year: 1998
Main classification: C07C229
IPC codes: C07C215, C07C213, C07C233, C07C229, C07C309, C07C45, C07C227