SYNTHESIS OF SOME NOVEL CHALCONES AND THEIR FACILE ONE-POT CONVERSION TO 2-AMINOBENZENE-1, 3-DICARBONITRILES USING MALONONITRILE

A facile synthesis of some novel chalcones (3a-3k) by the condensation of variously substituted aromatic aldehydes and 2,4-dihydroxyacetophenone and their subsequent rapid one pot transformations to 2-aminobenzene-1,3-dicarbonitriles (5a-5k) with malononitrile and morpholine has been described. It is a comparative study of synthesizing these novel compounds by conventional as well as non-conventional microwave irradiation in a commercially modified microwave oven and also confirms the possible intervention of specific (non-thermal) microwave effect. The present investigation also focused on the remarkable reaction rate enhancement by the use of various inorganic solid supports in non-conventional microwave irradiation which minimizes the hazards of solution phase reactions. The non-conventional protocol offers several advantages such as simple procedure, fast reaction rate, mild reaction condition and improved yields as compared to conventional methods. The structures of newly synthesized compounds have been established on the basis of elemental analysis, 1H NMR, Mass and IR spectral data.