NOVEL BETA-LACTAM COMPOUNDS AND PROCESS FOR PREPARING THE SAME

摘要

A beta -lactam compound of the formula: <CHEM> wherein R<1> is lower alkyl or OH-substituted lower alkyl, R<2> is H or lower alkyl, X is O, S or NH, n is 1 to 3, R<3> is -C(R<a>)=NH (R<a> is H, lower alkyl or substituted lower alkyl), or a salt thereof, or an ester thereof. These compounds show excellent antibacterial activity against Gram-positive bacteria, particularly against methicillin-resistant Staphylococci and methicillin-resistant and coagulase-negative Staphylococci.