Studies on antipeptic ulcer agents: a structure-activity relationship analysis of aldehyde semicarbazones and aryl hydrazones.
Twenty-eight condensation products of heterocyclic-a-carboaldehydes with N-aminooxazolidones, semicarbazides, thiosemicarbazides and benzoxycarbonyl hydrazide were synthesized so as to deduce the antiulcer pharmacophore or fragment of furazolidone (I), a prototype which has shown therapeutic efficacy in patients with gastric and duodenal ulcers. SAR analysis of the compounds indicated that the substitution of furan, thiophene, pyrrole or N-methyl pyrrole rings for 5-nitrofuran and the cleavage of the oxazolidone ring did not fully destroy the activity. The electron density of the carbonyl group was found to be of importance. A lead structure, therefore, was derived for further optimization.