2BETA-SUBSTITUTED-METHYLPENICILLANIC ACID DERIVATIVES, AND SALTS AND ESTERS THEREOF

摘要

Disclosed is a process for preparing 2 beta -substituted-methylpenicillin derivative of the formula wherein R is H or carboxyl protecting group, R1 is H or halo, R2 is H, lower alkyl, lower alkoxy, halogen, azido, lower alkylthio, phthalimide or a group -NHR3 (wherein R3 is H or acyl), and - @@@@ is an optionally substituted monocyclic or bicyclic heterocyclic group having 1 to 4 nitrogen atoms in the ring structure, the process comprising reacting a compound of the formula wherein X is Cl or Br, and R, R1 and R2 are as defined above with a heterocyclic compound of the formula H- @@@@ (III) wherein - @@@@ is as defined above. m