Effective synthesis of some novel 7,8-substituted coumarins through Heck reaction and Sonogashira’s coupling reactions

Abstract

Abstract-In this paper we would like to report the synthesis of medicinally active 7,8-substituted coumarins were attempted by using the Heck reaction of iodocoumarin with olefin to gave product 7, 8-substituted chromenyl maleate is accomplished by the use of an organ palladium catalyst, and a base. Sonogashira coupling reaction of 8-iodo umbelliferone with propargyl alcohol to gave product coumarin substituted propargyl alcohol by using freshly prepared tetrakis(triphenylphosphine)palladium catalyst and copper (I) iodide in dry THF was carried out.A carbon-carbon single bond formed in both the coupling reactions and good yields are obtained.