Rapid and selective free radical monochlorination of the (la-d) substituted -4-methyl coumarines was achieved using sodium hypochlorite under microwave conditions to synthesize substituted-4-chloromethyl coumarines(2a-d)of anticipated antifungal activity,while irradiation using the assistance of IR lamp was failed to chlorinate these derivatives. The advantages of Microwave irradiation provide shorter reaction times, and higher yields . The structures of these compounds were confirmed by IR&uv Spectrophotometei.