摘要:
Disclosed are a method for producing racemic piperidine derivatives by processing optically-active piperidine derivatives in a hydrogen atmosphere in the presence of a reducing catalyst; and a method for producing optically-active piperidine derivatives or their acid salts by optically resolving the racemic piperidine derivatives obtained in the former method.
摘要:
Optically-active 2-piperazinecarboxylic acid derivatives are produced through diastereomer salt resolution using optically-active acidic amino acid derivative as the resolving reagent. In this method, the recovery of the resolving reagent used is high, and the production efficiency to produce the optically-active products is high. As the optically-active acidic amino acid derivatives, usable are optically-active, N-acylated acidic amino acid derivatives and optically-active, N-sulfonylated acidic amino acid derivatives.
摘要:
An industrial process for producing O,O'-diacyltartaric anhydride with high purity and high efficiency is disclosed. According to the process of the invention, a carboxylic acid of the formula (I):R.sup.1 COOH (I)(wherein R.sup.1 represents C.sub.1 -C.sub.4 alkyl group; phenyl group; or phenyl group substituted with 1-5 C.sub.1 -C.sub.4 alkyl groups or with 1-5 halogen atoms) is reacted with tartaric acid in the presence of a chlorinating agent.
摘要:
When a salt of an amine and an optically active diacyltartaric acid, or a diastereomer salt of an optically active amine and an optically active diacyltartaric acid, obtained by optically resolving a racemic amine using the optically active diacyltartaric acid, is salt-exchanged with an acid aqueous solution, the optically active diacyltartaric acid is added in the acid aqueous solution beforehand.Furthermore, a raw material containing a racemic amine and an optically active diacyltartaric acid is optically resolved, and the diastereomer salt of the optically active amine and the optically active diacyltartaric acid respectively of one isomer type, is separated. The obtained diastereomer salt is dissociated using an acid aqueous solution containing the optically active diacyltartaric acid, for recovering the optically active diacyltartaric acid, and the obtained optically active diacyltartaric acid is recycled into an optical resolution step as a raw material of the optical resolution step.
摘要:
When a salt of an amine and an optically active diacyltartaric acid, or a diastereomer salt of an optically active amine and an optically active diacyltartaric acid, obtained by optically resolving a racemic amine using the optically active diacyltartaric acid, is salt-exchanged with an acid aqueous solution, the optically active diacyltartaric acid is added in the acid aqueous solution beforehand. Furthermore, a raw material containing a racemic amine and an optically active diacyltartaric acid is optically resolved, and the diastereomer salt of the optically active amine and the optically active diacyltartaric acid respectively of one isomer type, is separated. The obtained diastereomer salt is dissociated using an acid aqueous solution containing the optically active diacyltartaric acid, for recovering the optically active diacyltartaric acid, and the obtained optically active diacyltartaric acid is recycled into an optical resolution step as a raw material of the optical resolution step.
摘要:
If an organic solvent with a water content of 15% or less is used when an oxycarbonyl-substituted piperazine derivative is produced from a piperazine derivative, the piperazine derivative can be oxycarbonylated.
摘要:
In producing optically-active amino acid benzyl esters by reacting optically-active amino acids with benzyl alcohols, hydrazines are present in the reaction system, or the compounds are reacted in the absence of oxygen, or the compounds are reacted in the absence of oxygen while hydrazines are present in the reaction system. The processes are simple and give optically-active amino acid benzyl esters of high optical purity.
摘要:
A method for producing pyrrolidine derivatives such as 3,4-epoxypyrrolodines, 3-pyrrolidols and the like, by oxidizing 3-pyrrolines with at least one peroxide in the presence of at least one acid is disclosed. The 3-pyrrolines are produced by deriving cis-2-butene compounds from cis-2-butene-1,4-diols and performing a cyclization between the cis-2-butene derivatives and at least one primary amine. The method may be performed as a one-pot synthesis and may be performed as a continuous reaction.
摘要:
A method for making an optically active 3-aminopyrrolidine-2,5-dione derivative represented by the formula (3) includes cyclizing an optically active asparagine ester derivative represented by the formula (1) or (2), or an acid salt thereof. A method for making an optically active 3-aminopyrrolidine derivative represented by the formula (9) includes reducing the optically active 3-aminopyrrolidine-2,5-dione derivative represented by the formula (3). A method for making an optically active 3-aminopyrrolidine derivative includes hydrogenolyzing the optically active 3-aminopyrrolidine derivative represented by the formula (9).
摘要:
Process for producing an optically active ester by reaction of a racemic alcohol with an optically active amino or tartaric acid derivative, a process for producing an optically active alcohol by hydrolysis of the optically active ester, a process for converting an alcohol into a ketone by oxidation, a method for stably storing an optically active ketone, and a new optically active amino acid ester and a new optically active tartaric acid ester.