A one-pot condensation for synthesis 2-methyl-4-phenylpyrano[3,2-c] chromen-5(4H)-one and synthesis of warfarin by ionic liquid catalysis

The anticoagulant racemic warfarin is synthesized by the michael addition of 4-hydroxycoumarin with benzalacetone in the present of equimolar amounts of imidazolium based ionic liquids [bmim] bf4and [bmim] br and other reaction solvents such as h2o,pyridine and ammonia in five different tests. also synthesis of a derivative of warfarin (2-methyl-4-phenyl pyrano [3,2-c] chromen-5(4h)-one) under solvent-free condition is reported. in this paper,we show the potential that ionic liquid have for the development of green methods for the formation of the c-c bond by reaction condensations without catalysts and organic solvents. a ‘green method,according to the well-known principles,must reduce or eliminate the use or generation of unsafe substances. the work-up procedures were fairly simple and the products don’t require further purification. © 2016 by school of pharmacy.