A number of ranitidine analogues in which the diamino-1, 2, 5-thiadiazole 1-oxide substructure bearing alkyl chains of different length is present as the urea equivalent group, were synthesised and studied for their lipophilic and H2 antagonist properties. Derivatives which displayed a logP≤ 3 behaved as competitive antagonists of histamine at H2 receptors present on guinea pig right atrium. The remaining more lipophilic members of ...
[Lumma, William C.; Anderson, Paul S.; Baldwin, John J.; Bolhofer, William A.; Habecker, Charles N.; et al. Journal of Medicinal Chemistry, 1982 , vol. 25, # 3 p. 207 - 210]