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:
Mar. 24, 2009
Filed:
Sep. 06, 2004
Nobuo Matsumoto, Tokyo, JP;
Hiroshi Kawakabe, Tokyo, JP;
Yasuko Manabe, Tokyo, JP;
Nippon Chemical Industrial Co., Ltd., Tokyo, JP;
Abstract
An industrially advantageous process for producing 3-chloromethyl-3-cephem derivative crystals. The process for 3-chloromethyl-3-cephem derivative production comprises: a first step in which a thiazolineazetidinone derivative (1) is reacted with a sulfonyl halide (2) in the presence of an acid in a solvent to obtain an azetidinone derivative (3); a second step in which the azetidinone derivative (3) is reacted with a chlorinating agent in an organic solvent to obtain a chlorinated azetidinone derivative (4); and a third step in which the chlorinated azetidinone derivative (4) is reacted with an alcoholate (5) at a pH of 8 or lower in a solvent comprising an alcohol and an ether and a 3-chloromethyl-3-cephem derivative (6) is recovered in the form of crystals.