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:
Feb. 03, 1976
Filed:
Nov. 12, 1973
Applicant:
Inventors:
Yasuo Fujimoto, Yokohama, JA;
Keizo Tatsukawa, Machida, JA;
Yoichi Koiwa, Tokyo, JA;
Akira Miike, Machida, JA;
Tatsuo Nomura, Tokyo, JA;
Shohei Kobayashi, Kooriyama, JA;
Assignee:
Kyowa Hakko Kogyo Kabushiki Kaisha, Tokyo, JA;
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
2603 / ;
Abstract
This invention relates to an improved process for preparing N-carboxylic anhydrides of amino acids, and N-carboxylic anhydrides of derivatives of amino acids by reacting an amino acid, a derivative of amino acid or a salt thereof with trichloromethylchloroformate in an organic solvent, preferably a mixture of an ether or ester with one or more other organic solvents and adding to the reaction mixture carbon, basic aluminum chloride or aluminum oxide just before or immediately after completion of the initial reaction.