Otsuka Kagaku Kabushiki Kaisha

Otsuka Kagaku Yakuhin Kabushiki Kaisha

Shigemitsu Nagao

Michio Sasaoka

Hideo Tanaka

Sigeru Torii

Yutaka Kameyama

Takashi Shiroi

Norio Saito

Ryo Kikuchi

Masatoshi Taniguchi

Yuzuru Ogata

Nori Saito

This invention provides a method of producing a .beta.-lactam derivative represented by the formula (I): ##STR1## said method consisting essentially of the step of reacting a .beta.-lactam derivative represented by the formula (II): ##STR2## with a phenol in a reaction system which consists essentially of said .beta.-lactam derivative of formula (II) and said phenol.

Method for production of .beta.-lactam derivatives

Disclosed is a method of producing a 3-exomethylenecepham of the formula ##STR1## wherein R.sup.1 is amino or substituted amino and R.sup.2 is a carboxy-protecting group comprising reacting a cephem of the formula ##STR2## wherein R.sup.1 and R.sup.2 are as defined above and X is halogen with lead metal while maintaining the pH of the reaction system at about 0.1 to 8. The cephem (I) may be reacted with a catalytic amount of lead metal or a lead compound in the presence of a metal having a greater ionization tendency than lead.

Method for production of 3-exomethylenecepham derivatives

A process for preparing an azetidinone derivative represented by the formula (I) ##STR1## wherein R.sup.1 represents an aryl group, arylmethyl group or aryloxymethyl group, R.sup.2 represents hydrogen atom or a carboxyl-protecting group and R.sup.3 represents an alkyl group or aryl group, the process comprising reacting an azetidinone derivative represented by the formula (II) ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above with a chlorinating agent.

Halogenation process for preparing

A process for preparing an azetidinone derivative represented by the formula ##STR1## wherein R.sup.1 is hydrogen, halogen or lower alkoxy, R.sup.2 is hydrogen, halogen, lower alkoxy, amino or a group ##STR2## (in which R.sup.5 is substituted or unsubstituted phenyl, substituted or unsubstituted phenylmethyl, substituted or unsubstituted phenoxymethyl, or substituted or unsubstituted benzoyl), or R.sup.1 and R.sup.2, when taken together, are carbonyl, R.sup.3 is substituted or unsubstituted phenyl, and R.sup.4 is hydrogen, optionally substituted hydrocarbon residue or acyl, silyl, sulfonyl or phosphonyl derived from inorganic acid or organic acid, the process comprising reacting a dithioazetidinone derivative represented by the formula ##STR3## wherein R.sup.1, R.sup.2 and R.sup.4 are as defined above and R.sup.9 is substituted or unsubstituted, nitrogen-containing aromatic heterocyclic residue with a compound represented by the formula

Process for preparation of 4-sulfonylthio azetidinone derivatives

Growing community of inventors

Mobara, Japan

Shigemitsu Nagao