Cholinergic agents structurally related to furtrethonium. 3. Synthesis and antimuscarinic activity of a series of N-(5-methyl-2-furfuryl and-tiophenyl)-dialkyl amines and of 2-dimethylamino methyl-4-(1'-substituted-acetoxy-methyl)-1,3-dioxolanes.

The introduction of an homologous series of cyclic amines at position 2 of 5-methylfurane and its isoster 5-methylthiophene induced a weak antagonist behaviour, probably depending on the steric hindrance of the substituents at the nitrogen, in the case of the cardiac tissue. Surprisingly, when evaluated on guinea-pig ileum preparatons, these compounds showed non-muscarinic effects, not-related either to nicotinic or istaminergic effects, the nature of which awaits to be explained. Substitution of the furane ring on the structure of the lead 2a, b, obtained in a previous study, with the bioisoster 1,3-dioxolane moiety gave potent but not selective analogues (17 and 18).