Otsuka Kagaku Kabushiki Kaisha

Otsuka Chemical Co., Ltd.

Taiho Pharmaceutical Company Limited

Isao Wada

Michio Sasaoka

Yutaka Kameyama

Hideo Tanaka

Sigeru Torii

Yasuhisa Amano

Yoshihisa Tokumaru

Akihiro Shimabayashi

Ichiro Kawahara

An object of the invention is to provide an industrially advantageous process capable of remarkably suppressing the generation of an undesirable by-product cepham compound to thereby efficiently produce a desired 2&#x3b1;-methyl-2&#x3b2;-[(1,2,3-triazol-1-yl)methyl]penam-3&#x3b1;-carboxylic acid ester. In the present invention, a diphenylmethyl 2&#x3b2;-bromomethyl-2&#x3b1;-methylpenam-3&#x3b1;-carboxylate (BMPB) is reacted with 1,2,3-triazole in a halogenated hydrocarbon solvent at &#x2212;5&#xb0; C. or lower. The reaction in a halogenated hydrocarbon solvent at &#x2212;5&#xb0; C. or less can remarkably suppress the generation of an undesirable by-product cepham compound, so that the desired diphenylmethyl 2&#x3b1;-methyl-2&#x3b2;-[(1,2,3-triazol-1-yl)methyl]penam-3&#x3b1;-carboxylate (TMPB) can be efficiently produced.

Process for producing penam compound useful for preparing tazobactam

The present invention provides 2&#x3b2;-chloromethyl-2&#x3b1;-methylpenam-3&#x3b1;-carboxylic acid benzhydryl ester (CMPB) crystals of excellent stability, and a process for producing the CMPB crystals comprising the steps of (A) concentrating a solution containing CMPB; (b) subjecting the thus-obtained concentrate to column chromatography; (C) concentrating a CMPB-containing fraction; and (D) dissolving the thus-obtained CMPB-containing concentrate in an ether solvent and adding a hydrocarbon solvent to the resulting solution to precipitate CMPB crystals.

Penicillin crystals and process for producing the same

A process for preparing an allenyl .beta.-lactam compound represented by the formula (4), characterized by reacting the hydroxyl group of a .beta.-lactam compound represented by the formula (1) with a reactive functional group derivative of sulfonic acid represented by the formula (2) to convert the compound of the formula (1) to a .beta.-lactam compound represented by the formula (3), thereafter reacting the resulting .beta.-lactam compound with a basic anion exchange resin of the type having a tertiary organic base fixed to the resin and isolating the resulting allenyl .beta.-lactam compound of the formula (4) from the reaction mixture ##STR1##

Process for preparing .beta.-lactam derivatives

Cyclization for preparing halo-cephems

Process for producing diazomethane derivatives

Growing community of inventors

Tokushima, Japan

Isao Wada