Coumarin is the best known oxygenated heterocycle amongst all the isomeric benzopyranones. In view of their extensive plant origin and diverse biological properties, a large number of compounds containing coumarin nucleus have been synthesised. During the present investigation, derivatives of coumarin have been chosen as a model system of oxygen heterocycles. Attempts have been made towards the synthesis of some new structurally interesting and biologically active compounds. These compounds have also been tested for their pharmacological activities.