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:
Jan. 31, 1989
Filed:
Mar. 22, 1988
Ryuichi Mita, Kawasaki, JP;
Takeshi Oura, Zushi, JP;
Chojiro Higuchi, Kamakura, JP;
Toshio Katoh, Kawasaki, JP;
Akihiro Yamaguchi, Kamakura, JP;
Mitsui Toatsu Chemicals, Incorporated, Tokyo, JP;
Abstract
This invention relates to an improved process for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester. More specifically, it relates to a process for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester which comprises treating, as a raw material, N-formyl-.alpha.-L-aspartyl-L-phenylalanine in methanol in the presence of an acid to form .alpha.-L-aspartyl-L-phenylalanine dimethyl ester, hydrolyzing the .alpha.-L-aspartyl-L-phenylalanine dimethyl ester by bringing it into contact with hydrochloric acid in the presence of methanol as desired, separating the thereby-precipitated .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride and neutralizing the hydrochloride. Further, this invention also provides a process for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester capable of using, as a raw material, N-formyl-.alpha.-L-aspartyl-L-phenylalanine which contains N-formyl-.beta.-L-aspartyl-L-phenylalanine in an amount of 30% by weight or less.