Experimental antiulcer drugs.4. 1,3-Disubstituted 2,4,5,6-tetrahydro-4,6,6...

The synthesis of 1,3-disubstituted 2,4,5,6-tetrahydro-4,6,6-trimethyl-2-phenylcyclopenta[c]pyrrole-4-carboxamides is reported. The derivatives included R1 = R3 = H, R1 = CH2OH with R3 = H (16) or CH3, R1 = CH3 with R3 = CH2OH (17), and R1 = R3 = CH2OH. The monohydroxymethyl derivatives were as active as the parent cyclopentapyrrole, where R1 = R3 = CH3 (1), when administered orally in the pyloric ligated rat. The compounds lacking one or both CH3 groups at C-1 or C-3 were much less active. Compounds 16 and 17 inhibited histamine-induced gastric acid secretion in the dog.