Abstract: A method of producing an optically active 2-methylpiperazine includes: adding a solvent to a solution of the optically active 2-methylpiperazine to carry out solvent replacement, and then being crystallized to obtain crystals of the optically active 2-methylpiperazine. The method allows the optically active 2-methylpiperazine to be purified during the crystallization process, and thus it is possible to obtain an optically active 2-methylpiperazine having a high quality.

Abstract: A method of producing an optically active 2-methylpiperazine includes: adding a solvent to a solution of the optically active 2-methylpiperazine to carry out solvent replacement, and then being crystallized to obtain crystals of the optically active 2-methylpiperazine. The method allows the optically active 2-methylpiperazine to be purified during the crystallization process, and thus it is possible to obtain an optically active 2-methylpiperazine having a high quality.

Abstract: A method produces optically active trans-1,2-diaminocyclohexane, in which a crystal of optically active trans-1,2-diaminocyclohexane is obtained by crystallization from a solution of optically active trans-1,2-diaminocyclohexane. Optically active trans-1,2-diaminocyclohexane with high purity is obtained in a favorable yield from a solution of optically active trans-1,2-diaminocyclohexane. The optically active trans-1,2-diaminocyclohexane with high purity is useful as a raw material for a large number of medicines.

Abstract: 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.

Abstract: A nitrogenous heterocyclic compound such as 3-aminopyrrolidine derivative is produced by hydrogenolysis of an N-substituted nitrogenous heterocyclic compound with normal pressure hydrogen in a water-based solvent in presence of a catalyst. In the case an optically active 1-substituted-3-aminopyrrrolidine derivative is used as a raw material, an optically active 3-aminopyrrolidine derivative can be obtained as a product practically without racemination.

Abstract: 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.

Abstract: An optical-active cis-piperidine derivative of high chemical purity and high optical purity is efficiently produced through optical resolution of a cis-piperidine derivative mixture, racemic cis-piperidine derivative with an optical-active tartaric acid derivative or an optical-active amino acid derivative. For the optical-active tartaric acid derivative, preferred are optical-active di(paratoluoyl)tartaric acid and optical-active di(4-methoxybenzoyl)tartaric acid; and for the optical-active amino acid derivative, preferred is optical-active N-benzenesulfonylphenylalanine.

Abstract: .gamma.-GTP activity can be determined easily by using a stabilized substrate solution comprising .gamma.-L-glutamyl-p-nitroanilide and a modified cyclodextrin, together with an acceptor solution containing an acceptor for glutamic acid and measuring p-nitroaniline generated.

Abstract: A fuel injection device is disposed in a fuel supply passageway and adapted to control the amount of injection by controlling the opening time and/or opening area of a gate controlled in connection with engine rpm and the amount of suction air. The difference between the fuel supply pressure and the negative pressure in a suction pipe is maintained constant by a pressure regulator. The device contains a mechanism for compensating fuel supply pressure according to fuel temperature.