摘要:
An optically active amino acid derivative is produced by N-protecting an optically active 3-haloalanine derivative followed by cyclization, or cyclizing this derivative followed by N-protection to thereby give an optically active N-protected-aziridine-2-carboxylic acid derivative which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent, or by N-protecting an optically active 3-haloalanine derivative to thereby give N-protected-aziridine-2-carboxylic acid which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent. According to this process, natural and unnatural optically active amino acids can be produced from inexpensive materials by using simple procedures.
摘要:
An optically active amino acid derivative is produced by N-protecting an optically active 3-haloalanine derivative followed by cyclization, or cyclizing this derivative followed by N-protection to thereby give an optically active N-protected-aziridine-2-carboxylic acid derivative which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent, or by N-protecting an optically active 3-haloalanine derivative to thereby give N-protected-aziridine-2-carboxylic acid which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent. According to this process, natural and unnatural optically active amino acids can be produced from inexpensive materials by using simple procedures.
摘要:
An optically active amino acid derivative is produced by N-protecting an optically active 3-haloalanine derivative followed by cyclization, or cyclizing this derivative followed by N-protection to thereby give an optically active N-protected-aziridine-2-carboxylic acid derivative which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent, or by N-protecting an optically active 3-haloalanine derivative to thereby give N-protected-aziridine-2-carboxylic acid which is protected by a benzenesulfonyl group substituted by nitro at the 2- and/or 4-positions and then treating this product with an organic metal reagent. According to this process, natural and unnatural optically active amino acids can be produced from inexpensive materials by using simple procedures.
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 process for simply producing an optically active 2-thiomethyl-3-phenylpropionic acid derivative useful as an intermediate for medicines from inexpensive raw materials. An optically active 2-hydroxymethyl-3-phenylpropionic acid ester derivative which can be relatively easily obtained by asymmetric reduction reaction with an enzyme is cyclized to an optically active P-lactone derivative which is then reacted with a sulfur compound to produce an optically active 2-thiomethyl-3-phenylpropionic acid derivative in high yield.
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 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 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:
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:
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.