Efficient and rapid conversion of 3-amino imidazo[1,2-a] pyridin-2-yl)-4H-chromene-4-ones to its corresponding thio analogues using Lawesson’s reagent

: An expeditious, efficient and high yield conversion of ketone group in GBB adducts was obtained by the reaction with 3-formyl chromone, 2-amino pyridine and isocyanide to corresponding thio analogues is described utilizing Lawesson’s reagent. The reaction was involved microwave irradiation for both GBBR and the functional group transformation from ketone to thio ketone using Lawesson’s reagent through sequential fashion. The thio heterocyclic analogs of GBB products were characterized by using NMR.