摘要:
The present invention provides an industrially available method for efficiently producing high-purity S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid excellent in solid-liquid separability from an S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester, and also provides products obtained by the method.Under a temperature condition of 50-80° C. in an aqueous solvent, (A) an S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester represented by the general formula (1) is hydrolyzed under a basic condition for 1-3 hours; then (B) the insoluble matters contained in the reaction solution resulting from the hydrolysis are removed; and (C) an acid is added to the resulting solution to effect crystallization; provided that R in the general formula (1) represents an alkyl or aryl group.
摘要:
The present invention provides an industrially available method for efficiently producing high-purity S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid excellent in solid-liquid separability from an S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester, and also provides products obtained by the method.Under a temperature condition of 50-80° C. in an aqueous solvent, (A) an S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester represented by the general formula (1) is hydrolyzed under a basic condition for 1-3 hours; then (B) the insoluble matters contained in the reaction solution resulting from the hydrolysis are removed; and (C) an acid is added to the resulting solution to effect crystallization; provided that R in the general formula (1) represents an alkyl or aryl group.
摘要:
Disclosed is a process for producing an optically active indoline-2-cabroxylic acid or a derivative thereof, which is useful as a raw material for synthesis of pharmaceuticals or the like, from an indoline-2-cabroxylic acid in an industrially advantageous manner.An indoline-2-cabroxylic acid is converted into an N-substituted-indoline-2-carboxylic acid, and then is esterified using a biocatalyst having a stereoselectivity in an organic solvent containing an alcohol. Next, an alkali is used to obtain an optically active N-substituted-indoline-2-carboxylic acid ester and an optically active N-substituted-indoline-2-cabroxylic acid or a salt thereof, and then the two optically active substances are separated utilizing distribution properties thereof in an organic solvent/water system. Further, the two substances are hydrolyzed and deprotected, whereby the optically active indoline-2-cabroyxlic acid or a derivative thereof, which is useful as a raw material for synthesis of pharmaceuticals or the like, can be produced and provided economically.
摘要:
In the method for producing an optically active chromancarboxylate of the present invention, one of the enantiomers of racemic chromancarboxylic acid is esterified in a solvent containing an alcohol in the presence of a biocatalyst. After the esterification, the other enantiomer, i.e., the non-reacted chromancarboxylic acid is separated out of the reaction mixture to obtain the aimed optically active ester. The optically active chromancarboxylate is useful as the material for medicines, agricultural chemicals, etc. The invention provides an efficient production method thereof which is industrially applicable.
摘要:
The invention provides a process for producing a chroman compound represented by formula (1), characterized in that the process includes allowing a phenol, an unsaturated compound, and a formaldehyde to react in the absence of catalyst and in the presence of water in an amount by mole 1 to 10 times that of the phenol.According to the present invention, a high-purity chroman compound can be produced in the absence of catalyst and under mild conditions. In addition, the invention provides an industrial means for producing the compound, without using a large amount of an acid or a base serving as a reaction promoter or a catalyst, which would otherwise cause side reactions, apparatus corrosion, etc.
摘要:
The invention provides a process for producing a chroman compound represented by formula (1), characterized in that the process includes allowing a phenol, an unsaturated compound, and a formaldehyde to react in the absence of catalyst and in the presence of water in an amount by mole 1 to 10 times that of the phenol. According to the present invention, a high-purity chroman compound can be produced in the absence of catalyst and under mild conditions. In addition, the invention provides an industrial means for producing the compound, without using a large amount of an acid or a base serving as a reaction promoter or a catalyst, which would otherwise cause side reactions, apparatus corrosion, etc.
摘要:
The present invention is a simple method, in which a specific amount of alkali is added to an enantiomeric mixture of an optically active organic carboxylic acid where enantiomers are present in a non-equimolar ratio, or in which the enantiomeric mixture of an optically active organic carboxylic acid is neutralized with an alkali, and then a specific amount of acid is added thereto, thereby separating an organic carboxylic acid salt in the mother liquor and a crystallized organic carboxylic acid from each other. The method makes it possible to obtain an optically active organic carboxylic acid with improved enantiomeric excess. The present invention provides a simple production method for obtaining an optically active organic carboxylic acid with improved enantiomeric excess from an enantiomeric mixture of an optically active organic carboxylic acid where enantiomers are present in a non-equimolar ratio.
摘要:
5-Tolyl-pent-2-ene is cyclized in liquid phase in the present of an aliphatic hydrocarbon to produce the corresponding dimethyltetralin. The use of the aliphatic hydrocarbon effectively prevents a side reaction such as dimerization of 5-tolyl-pent-2-ene to provide dimethyltetralin in a high yield. Also, 5-tolyl-pent-2-ene is cyclized in liquid phase or vapor phase in the presence of a catalyst comprising a carrier supporting sulfate ions to produce the corresponding dimethyltetralin. The catalyst supporting sulfate ions shows a high catalytic activity event at low temperatures. Therefore, the cyclization of 5-tolyl-pent-2-ene is conducted in a wide temperature range from low temperatures to high temperatures.