NEW 2-OXYIMINO-3-OXOBUTYRIC ACID DERIVATIVES AND PROCESS FOR PREPARATION THEREOF

摘要

A cephem compound of the formula: …… wherein… R<1> is amino substituted thiazolyl which may have halogen(s),… protected amino substituted thiazolyl which may have halogen(s),… lower alkylamino substituted thiazolyl, amino substituted thiadiazolyl,… protected amino-substituted thiadiazolyl, amino substituted pyridyl,… protected amino substituted pyridyl, furyl, thiazolyl, thiadiazolyl, phenyl, or naphthyl,… R<2> is carboxy(lower)alkyl or protected carboxy(lower)alkyl,… R<3> is lower alkylthio, and… R<4> is carboxy or protected carboxy,… and pharmaceutically acceptable salts thereof, and processes for their preparation, and also a pharmaceutical composition comprising, as an active ingredient, the above compound or its pharmaceutically acceptable salt. …The invention also relates to intermediate compounds.