Potential histamine H2-receptor antagonists. Synthesis, conformational studies and activity of novel 3-oxo-1,2,5-thiadiazole 1,1-dioxide derivatives.

New histamine H2-receptor antagonists bearing a novel "urea equivalent", the 3-oxo-1,2,5-thiadiazole 1,1-dioxide ring, have been synthesized in a transamination reaction. Open chain derivatives have also been obtained. Theoretical conformational analysis of the compounds has been carried out using a molecular modelling program. Semiempirical CNDO/2 calculations have also been performed. The antisecretory and cytoprotective activities of the compounds have been evaluated.