EP0771803A1 — Pyrazolo(1,5-a)pyrimidinium substituted cephem derivatives, their preparation and their use as antimicrobial agents

USPTO Abstract

The present invention relates to novel cephem compounds of formula (I): wherein R 1 is hydrogen or an amino protecting group; R 2 is hydrogen, a lower or fluoromethyl; R 3 is hydrogen, a lower alkyl, carboxyl or a protected carboxyl group; R 4 is hydrogen or a lower alkyl; R 5 is hydrogen, an anion or a carboxyl-protecting group; A is methylene or propenylene; X is an organic or inorganic anion, provided that X is excluded when R 5 is an anion; Q is nitrogen or CH, and the wavy line represents a bond of anti-form or syn-form, or a pharmaceutically acceptable salt thereof, their preparation and their use as antimicrobial agents, particularly, against Methicillin-Resistant Stapylococcus aureus (MRSA) and antimultipledrug-resistant bacteria. In a further aspect, the invention provides the compound of formula (V): which is a novel compound and an intermediate for producing of the compounds of formula (I).