A simple and efficient synthetic approach is reported for the synthesis of 5-trifluoromethyl-5-aryl-3-methylidenepyrrolidin-2-ones in moderate to excellent yields via an acid-catalyzed one-pot multicomponent reaction of aromatic trifluoromethyl ketones, acylhydrazines, and ethyl 2-(bromomethyl)acrylate promoted by tin powder. The protocol is operationally simple. The overall process involves allylation and cyclization of the intermediate of acylhydrazones.
β-Alkoxyvinyl trifluoromethyl ketones as efficient precursors for the one-pot synthesis of bis-(4,5-dihydro-1H-pyrazol-1-yl)methanones and 1H-pyrazolyl-1-carbohydrazides