NOVEL 2-SUBSTITUTED METHYL PENAM DERIVATIVES

摘要

Novel 2-substituted methyl penam derivatives include the formula (I), their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their solvates, their pharmaceutically acceptable salts, and pharmaceutical compositions containing them; wherein A = C or N; Het is a three- to seven-membered heterocyclic ring; R¹ represents carboxylate anion, or -COOR⁴ where R⁴ represents hydrogen, carboxylic acid protecting group or a pharmaceutically acceptable salt; R² and R³ may be same or different and independently represent hydrogen, halogen, amino, alkyl, protected amino, optionally substituted alkyl, alkenyl, alkynyl and the like; R represents substituted or unsubstituted alkyl, alkenyl, aryl, aralkyl, cycloalkyl, heterocyclyl or heterocyclylalkyl.