An improved method for preparation of cefpodoxime proxetil.

Cefpodoxime proxetil, a third-generation cephalosporin for oral administration, was synthesized by a method based on the following sequence of reactions: acylation of 7-aminocephalosporanic acid (7-ACA) with S-benzothiazol-2-yl(2-amino-4-thiazolyl)(methoxyimino)thioacetate (MAEM), chloroacetylation of the cefotaxime formed with chloroacetyl chloride, esterification of the acid function with 1-iodoethyl isopropyl carbonate and final cleavage of chloroacetamide protective group by treatment with thiourea in N,N-dimethylacetamide. The developed procedure allows us to obtain better yields of cefpodoxime proxetil and to eliminate the final purification step by column chromatography, necessary during the synthesis of this antibiotic by the previously reported methods.