Structural influences upon antihistamine activity; 3-amino-1-aryl-1-(2-pyridyl)propenes and related compounds

Abstract

Abstract A series of 3-amino-1-aryl-1-(2-pyridyl)propenes and related compounds have been prepared by the dehydration of corresponding tertiary alcohols, and the configurations of geometrical isomeric derivatives established from spectroscopic data. The ability of the aminopropenes to antagonize histamine-induced contractions of the guinea-pig ileum is reported. These data allow various structure-activity relations to be discussed including stereochemistry (cis 2-pyridyl/H geometry is superior to cis substituted phenyl/H but not necessarily to cis phenyl/H), nature of the basic function (1-pyrrolidino is markedly superior to either dimethylamino or 1-piperidino) and the importance of the vinylic hydrogen atom (sharp falls in potency follow its replacement by methyl).