An efficient,convenient and environmentally benign procedure for the synthesis of novel 3-oxo-3Hbenzo[a]pyrano[2.3-c]phenazine-l-carboxylate and 3-(5-hydroxybenzo[a]phenazin-6-yl) acrylate derivatives has been developed by domino three-component condensation reaction between 2-hydroxynaphthalene-1,4-dione,benzene-1,2-diamines and acetylenic esters in the presence of a catalytic amount of DABCO as an expedient,eco-friendly and reusable base catalyst in water.This green process produces biologically and pharmacologically significant heterocycles in a one-pot single operation and offers considerable advantages such as:operational simplicity,short reaction time,high yields,reusability of catalyst,absence of any tedious workup or purification and avoids hazardous reagents/solvents. An efficient, convenient and environmentally benign procedure for the synthesis of novel 3-oxo-3Hbenzo [a] pyrano [2.3-c] phenazine-l- carboxylate and 3- (5- hydroxybenzo [a] phenazin-6-yl) has been developed by domino three-component condensation reaction between 2-hydroxynaphthalene-1,4-dione, benzene-1,2-diamines and acetylenic esters in the presence of a catalytic amount of DABCO as an expedient, eco-friendly and reusable base catalyst in water. This green process produces biologically and pharmacologically significant heterocycles in a one-pot single operation and offers great effects such as: operational simplicity, short reaction time, high yields, reusability of catalyst, absence of any tedious workup or purification and avoids hazardous reagents / solvents.