A green approach to the synthesis of biologically important indeno[2,1-e]pyrazolo[5,4-b]pyridines via microwave-assisted multi-component reactions in water

A green approach to the synthesis of biologically important indeno[2,1-e]pyrazolo[5,4-b]pyridines was successfully realized via multi-component reactions of aldehyde, 3-methyl-1-phenyl-1H-pyrazol-5-amine and 1,3-indanedione in water under microwave irradiation without catalyst. This protocol has the prominent advantages of environmental-friendliness, short reaction time, excellent yields, low cost, easy operation as well as broad scope of applicability.