ULTRASOUND PROMOTED L- PROLINE CATALYZED FACILE SYNTHESIS AND ANTIMICROBIAL EVALUATION OF 4H-CHROMENO[2,3-D] PYRIMIDINE DERIVATIVES INCORPORATED WITH QUINOLINE MOIETY

A simple, straightforward synthesis of 5-(2-chloro-6-substitutedquinolin-3-yl)-2-(4-substitutedphenyl)-8,8- substituted-5,7,8,9-tetrahydro-4H-chromeno[2,3-d]pyrimidine-4,6(3H)-diones (4a-l) has been performed by ultrasound irradiation method. Targeted compounds (4a-l) prepared from reaction of intermediate 2-amino-4-(2-chloro-6-substituted quinolin-3-yl)-7,7-substituted-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3- carbonitrile 2, which is synthesized by one pot three components way using L-proline as green catalyst at room temperature, was further reacted with benzaldehyde derivatives in the same reaction mixture under ultrasound irradiation at 70oC. In this process, cyclization occurred through elimination of water molecule followed by intermolecular cyclization and finally dimroth rearrangement. All synthesized compounds were screened for their antimicrobial activity. We confirmed the synthesized compounds (4a-l) using 1H NMR, 13C NMR, IR and mass spectroscopic methods.