PROCESS FOR THE PREPARATION OF 3-CEPHEM COMPOUNDS

摘要

A process for preparing a 3-cephem compound represented by the formula (3), the process comprising the steps of reacting a beta -lactam compound represented by the formula (1) with a phosphorus halide compound in the presence of an organic base to give an imino- beta -lactam compound represented by the formula (2), adding a phenol to the same reaction system to cause decomposition due to reaction with an alcohol and simultaneously to remove the protection of carboxylic acid ester, giving a 3-cephem compound represented by the formula (3) or a salt thereof <CHEM> <CHEM> wherein R1, R2 R3 and X are as defined above.