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:
Sep. 15, 2020
Filed:
Sep. 12, 2017
Kyoto University, Kyoto-shi, Kyoto, JP;
Jun Hiratake, Kyoto, JP;
Bunta Watanabe, Kyoto, JP;
Ryuzo Yoshioka, Takatsuki, JP;
Hideaki Ishida, Ube, JP;
KYOTO UNIVERSITY, Kyoto-shi, Kyoto, JP;
NAHLS CORPORATION CO., LTD., Kyoto-shi, Kyoto, JP;
Abstract
Provided is a method for separating the four optical isomers of Nahlsgen. The method according to the present invention for producing a mixture of a D-2-amino-4-[(Rp)-(3-carboxymethylphenoxy)(methoxy)phosphoryl]butanoic acid hydrate and an L-2-amino-4-[(Sp)-(3-carboxymethylphenoxy)(methoxy)phosphoryl]butanoic acid hydrate includes subjecting a mixture of the four optical isomers, represented by Formula (1'), to fractional crystallization from water or from a solvent mixture of water and a water-soluble organic solvent, to precipitate a mixture of a compound represented by Formula (1-1′-1) and a compound represented by Formula (1-4′-1), where Formulae (1′), (1-1′-1), and (1-4′-1) are expressed as follows: