Studies on prodrugs. VIII. Preparation and characterization of (5-methyl-2-oxo-1,3-dioxol-4-yl) methyl esters of sulbactam and its analogs.

Several (5-methyl-2-oxo-1, 3-dioxol-4-yl)methyl esters of β-lactamase inhibitors were prepared and evaluated for oral absorbability. Sulbactam (5-methyl-2-oxo-1, 3-dioxol-4-yl)methyl ester (5a) was found to prodece a 5-fold higher serum level of sulbactam than sulbactam itself after oral administration to mice. The diester (15), in which ampicilling is bonded to the 5-methyl group of the above sulbactam ester (5a), was also prepared, but this diester (15) did not produce high serum levels of ampicillin and sulbactam after oral administration to mice.