The synthesis of a new series of 2-alkyl-4-pyrrolidinylthio-b-methylcarbapenems containing the substituted heteroaromatic moieties is described. Their in vitro antibacterial activities against both gram-positive and gram-negative bacteria were tested. The effect of substituents on the nitrogen atoms at heteroaromatic rings was investigated. Particular compounds (14 b, 14 c) containing 3-methyl- and 3, 5-dimethylpyrazolethio substituted moiety showed the most potent antibacterial activity.

Synthesis and Antibacterial Activities of 4-Pyrrolidinylthio Carbapenems: Containing Heteroaromatics as a Side Chain. -A variety of the new carbapenem derivatives (XI) (10 examples) are synthesized and evaluated for their in vitro antibacterial activities. Compounds (XIa) and (XIb) show the most potent activity. -(CHO, H.-W.; OH, C.-H.; LEE, J.-S.; LEE, S.-C.; CHOI, J.-H.; CHO*, J.-H.; Arch.