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] bf4 and [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) und...