NEW CEPHEM COMPOUND, ITS PRODUCTION AND ANTIMICROBIAL AGENT

PURPOSE:To produce the subject compound having an excellent antibacterial effect on a wide range of bacteria from Gram-positive bacteria including a staphylococcus to Gram-negative bacteria including a Pseudomonas aeruginosa and reduced in side effect by reacting specified compounds themselves. CONSTITUTION:The objective compound of formula IV (B is formula V or formula VI) is synthesized by reacting a compound of formula I [R is H, a metal atom, a carboxyl group-protecting group, etc. R is H, a lower alkoxy or formamide; R is H, an acyl, an amino group-protecting group; n is 0 or 1; X is an eliminable group with a compound of formula II (A is a five- membered heterocycle containing two N and one 0 or two N and one S; R is H, a lower alkyl, etc.; R is H, a halogen or a lower alkyl; R and R are each H or OH; M is H, a metal atom or quaternary ammonium) or a compound of formula III (R is H, a halogen or a lower alkyl; R is H or an aralkyl; R and R are each H or OH) and, as necessary, reducing it or removing the protective groups therefrom.