摘要:
The present invention provides a simple industrial process for producing an L- or D-optically active α-methylcysteine derivative or its salt, which is a useful pharmaceutical intermediate, from readily available, inexpensive raw materials. In a process for producing an L- or D-optically active α-methylcysteine derivative or its salt, a racemic N-carbamoyl-α-methylcysteine derivative or its salt is D-selectively cyclized with hydantoinase to produce a D-5-methyl-5-thiomethylhydantoin derivative or its salt and an N-carbamoyl-α-methyl-L-cysteine derivative or its salt, which are then subjected to deprotection of the amino group and the sulfur atom, and hydrolysis.
摘要:
The present invention relates to a process for producing an optically active 2-substituent-oxy-3-(4-substituent-oxyphenyl)propionic acid derivative which comprises stereoselectively reducing an 2-oxo-3-(4-substituent-oxyphenyl)propionic acid by an enzyme and subjecting the thus-obtained optically active 2-hydroxy-3-(4-substituent-oxyphenyl)propionic acid to esterification of the carboxyl group according to need, then to alkylation of the hydroxyl group and, if necessary, to deprotection of an ether type protective group. The present invention may make it possible to produce an optically active 2-substituent-oxy-3-(4-substituent-oxyphenyl)propionic acid derivative, which is useful as intermediates for the synthesis of medicinal compounds, efficiently, in a simple and easy manner, and commercially advantageously.
摘要:
An optically active N-protected azetidine-2-carboxylic acid (5) can be produced by preparing an optically active 4-amino-2-halobutyric acid (3) by halogenating an optically active 3-hydroxy-2-pyrrolidinone (1) with inversion of configuration to prepare an optically active 3-halo-2-pyrrolidinone (2) followed by hydrolysis or by halogenating an optically active 4-amino-2-hydroxybutyric acid ester (6) with inversion of configuration to prepare an optically active 4-amino-2-halobutyric acid ester (7) followed by hydrolysis or by halogenating the compound (6) with inversion of configuration to prepare the compound (7), cyclizing the same to prepare the compound (2) followed by hydrolysis, further cyclizing the compound (3) followed by treating the reaction product with an amino group-protecting agent. The thus-obtained compound (5) can be improved its optical purity further by recrystallization
摘要:
The invention provides a process for producing optically active azetidine-2-carboxylic acid with good efficiency, expedience, and commercial advantage, which comprises cyclizing an optically active 4-amino-2-halogenobutyric acid in an optical yield of as high as 90% or more. It is a process for producing optically active azetidine-2-carboxylic acid of the general formula (2), in which * denotes an asymmetric carbon atom, which comprises cyclizing an optically active 4-amino-2-halogenobutyric acid of the general formula (1), in which X represents a halogen atom and * denotes an asymmetric carbon atom, in the presence of an oxide of an alkaline earth metal, a hydroxide of an alkaline earth metal excepting barium, or an organic amine.
摘要:
The present invention provides a simple industrial process for producing an L- or D-optically active α-methylcysteine derivative or its salt, which is a useful pharmaceutical intermediate, from readily available, inexpensive raw materials. In a process for producing an L- or D-optically active α-methylcysteine derivative or its salt, a racemic N-carbamoyl-α-methylcysteine derivative or its salt is D-selectively cyclized with hydantoinase to produce a D-5-methyl-5-thiomethylhydantoin derivative or its salt and an N-carbamoyl-α-methyl-L-cysteine derivative or its salt, which are then subjected to deprotection of the amino group and the sulfur atom, and hydrolysis.
摘要:
An optically active N-protected azetidine-2-carboxylic acid (5) can be produced by preparing an optically active 4-amino-2-halobutyric acid (3) by halogenating an optically active 3-hydroxy-2-pyrrolidinone (1) with inversion of configuration to prepare an optically active 3-halo-2-pyrrolidinone (2) followed by hydrolysis or by halogenating an optically active 4-amino-2-hydroxybutyric acid ester (6) with inversion of configuration to prepare an optically active 4-amino-2-halobutyric acid ester (7) followed by hydrolysis or by halogenating the compound. (6) with inversion of configuration to prepare the compound (7), cyclizing the same to prepare the compound (2) followed by hydrolysis, further cyclizing the compound (3) followed by treating the reaction product with an amino group-protecting agent. The thus-obtained compound (5) can be improved its optical purity further by recrystallization.
摘要:
An optically active N-protected azetidine-2-carboxylic acid (5) can be produced by preparing an optically active 4-amino-2-halobutyric acid (3) by halogenating an optically active 3-hydroxy-2-pyrrolidinone (1) with inversion of configuration to prepare an optically active 3-halo-2-pyrrolidinone (2) followed by hydrolysis or by halogenating an optically active 4-amino-2-hydroxybutyric acid ester (6) with inversion of configuration to prepare an optically active 4-amino-2-halobutyric acid ester (7) followed by hydrolysis or by halogenating the compound (6) with inversion of configuration to prepare the compound (7), cyclizing the same to prepare the compound (2) followed by hydrolysis, further cyclizing the compound (3) followed by treating the reaction product with an amino group-protecting agent. The thus-obtained compound (5) can be improved its optical purity further by recrystallization
摘要:
An industrial advantage process for producing high-purity 3-hydroxytetrahydrofuran easily and simply, which comprises reducing a 4-halo-3-hydroxybutyric acid ester (1) with a boron hydride compound and/or an aluminum hydride compound as a reducing agent in an organic solvent immiscible with water; treating the reaction mixture with an acid and water to thereby effect conversion to the corresponding 4-halo-1,3-butanediol and at the same time giving an aqueous solution containing said compound; carrying out the cyclization reaction of the 4-halo-1,3-butanediol in said aqueous solution; extracting the resulting 3-hydroxytetrahydrofuran from the 3-hydroxytetrahydrofuran-containing aqueous solution using an organic solvent immiscible with water; and isolating the 3-hydroxytetrahydrofuran by concentration and/or distillation of the solution obtained.
摘要:
The present invention provides a method for easily producing an (R)-3-[4-(trifluoromethyl)phenylamino]-pentanoic acid amide derivative useful for an intermediate for pharmaceutical products, particularly an inhibitor of a cholesteryl ester transfer protein (CETP) from easily available raw materials. In the present invention, (S)-N-[4-(trifluoromethyl)phenyl]-3-hydroxypentanoic acid amide prepared from easily available raw materials leads a production of (R)-4-ethyl-1-[4-(trifluoromethyl)phenyl]-2-azetidinone to give (R)-3-[4-(trifluoromethyl)phenylamino]-pentanoic acid amide. Furthermore, (R)-4-ethyl-1-[4-(trifluoromethyl)phenyl]-2-azetidinone is reacted with a carbamic acid ester to give an (R)-3-[4-(trifluoromethyl)phenylamino]-pentanoic acid amide derivative.
摘要:
A process for preparing an enol silyl ether compound from a diazoacetoacetic acid ester having the general formula (IV): ##STR1## wherein R.sup.1 is a lower alkyl group having 1 to 6 carbon atoms, phenyl group, a substituted phenyl group, an aralkyl group or allyl group, and R.sup.2, R.sup.3 and R.sup.4 are the same or mutually different and each is a lower alkyl group having 1 to 6 carbon atoms, which comprises reacting a diazoacetoacetic acid ester having the general formula (I): ##STR2## wherein R.sup.1 is the same as defined above, with a trialkylsilyl chloride having the general formula (II): ##STR3## wherein R.sup.2, R.sup.3 and R.sup.4 are the same as defined above, in an inert solvent in the presence of an organic base and an alkali halide having the general formula (III):MX (III)wherein M is an alkaline metal and X is bromine atom or iodine atom. The desired compound is useful as an intermediate for synthesis of carbapenem .beta.-lactam antibiotics.