Synthesis and SAR study of novel 7-(pyridinium-3-yl)-carbonyl imidazo[5,1-b]thiazol-2-yl carbapenems

A new series of 1beta-methyl carbapenems, possessing a 7-substituted imidazo5,1-b]thiazol-2-yl group directly attached to the C-2 position of the carbapenem nucleus, was synthesized and evaluated for antibacterial activity. These compounds showed potent activities against Gram-positive bacteria, in particular methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant Streptococcus pneumoniae (PRSP). They also exhibited potent activity against beta-lactamase-negative ampicillin-resistant Haemophilus influenzae (BLNAR).