| abstract |
Abstract of the disclosure: Disclosed is a process for preparing 2.beta.-substituted-methylpenicillin derivative of the formula (I) 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 (II) wherein X is Cl or Br, and R, R1 and R2 are as defined above with a heterocyclic compound of the formula (III) wherein is as defined above. |