Intermediate of carbapenem antibiotics and process for the preparation thereof

A process for preparing the general formula (V) compound, wherein the general formula (XI) compound generated by reacting the general formula (I) with the general formula (X) compound is further under cyclization and esterification in situ.

• 42
• wherein R1, R2, R3, R4, and X are the same as defined above;
• R5, which is a protecting group of carboxyl to be easily removed by the common process, includes a lower alkyl, a lower alkenyl, a halogeno-lower alkyl, nitrobenzyl, a lower alkoxy-benzyl or benzhydryl;
• OA, which is an esterified hydroxy group which can be easily substituted by —S—R6 (R6 is the corresponding heterocyclic compound exhibiting antibiotic activity), includes —OP(O)(OR7)2 (R7 is aryl or a lower alkyl), a substituted or unsubstituted lower alkylsulfonyl (e.g., methanesulfonyl, ethanesulfonyl, trifluoromethanesulfonyl), aryloxycarbonyl (e.g., benzyloxycarbonyl).