The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 28, 1999
Filed:
Sep. 26, 1997
Tosoh Corporation, Yamaguchi, JP;
Abstract
A method for producing an optically active amino acid or derivative thereof having a high optical purity from an optically active amino acid comprising optical isomers or derivative thereof, which comprises any one of processes (A), (B), and (C), wherein the process (A) comprises the steps: (1) previously preparing an optically active amino acid or derivative thereof having an optical purity higher than a convergent value of a mutual solubility of the optical isomers and (2) crystallizing the optically active amino acid or the derivative thereof that exists in excess, said convergent value being a ratio of the desired optical isomer in the optical isomers dissolved in a mother liquor in which crystals of a racemate and an optically active compound coexist at equilibrium (the optical purity in a mother liquor). The processes (B) and (C) are described in the specification.