Abstract

Lithium bromide efficiently catalyses the three component condensation reaction of an aryl aldehyde, a 5,5-dimethyl-1,3-cyclohexanedione and ammonium acetate in ethanol, stirred at ambient temperature to afford the 1,4-dihydropyridines (1,4-DHP) in high yield and purity. The same protocol has been extended to the four-component reaction of an aryl aldehyde, 5,5-dimethyl-1,3-cyclohexanedione, ethyl acetoacetate and ammonium acetate for the preparation of polyhydroquinoline derivatives we got good to excellent yield shorter time duration.