Syntheses of Calix[4]Pyrroles by Amberlyst-15 Catalyzed Cyclocondensations of Pyrrole with Selected Ketones

Abstract
A facile and efficient protocol is reported for the synthesis of calix[4]pyrrolesand N-confused calix[4]pyrroles in moderate to excellent yields by reaction of dialkyl orcycloalkyl ketones with pyrrole catalyzed by reusable AmberlystTM-15 under eco-friendlyconditions.