A highly efficient green synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives and their photophysical studies

A task-specific ionic liquid, [Bmim]OH, has been used for an efficient synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones by one-pot cyclocondensation reaction of phthalhydrazide, aromatic aldehydes, and malononitrile or ethyl cyanoacetate under microwave irradiation. The advantages of this method include the use of green catalyst, no organic solvent, easy work-up and excellent yields. The photophysical properties for some 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives have been investigated for the first time.