Bismuth(III) nitrate pentahydrate - a mild and inexpensive reagent for synthesis of coumarins under mild conditions

Bismtuh(III) nitrate pentahydrate is found to be an efficient catalyst for the Pechmann condensation reaction of phenols and beta-ketoesters under solvent-free conditions. The reaction protocol is simple and is followed by aqueous work-up leading to the formation of the corresponding coumarin derivatives in good yield and high purity. (c) 2005 Elsevier Ltd. All rights reserved.