The work represented in the book is divided into five chapters in first chapter deals with derivatives of 4-amino coumarin. Second chapter developed a novel, rapid and efficient methodology for the synthesis of imidazo[1,2-a]pyridine derivatives. Third chapter deals with 1,3,4-oxadiazole. Fourth chapter modify known antiepileptic drug valproic acid to convert into various analogs. Fifth chapter deals with the biological activity of newly synthesized of 4-amino coumarin derivatives.