Microwave-Assisted Synthesis of Novel 2H-Chromene Derivatives Bearing Phenylthiazolidinones and Their Biological Activity Assessment

6-Hydroxy-2-oxo-2H-chromene-4-carbaldehyde (2), 6-chloro-2-oxo-2H-chromene-4-carbaldehyde (3) and 6-hydrazinyl-4-methyl-2H-chromen-2-one (5) were prepared as single-pharmacophore motif key intermediates. Compounds 2, 3 and 5 were incorporated in a series of multicomponent reactions (MCRs), under microwave assistance as well as conventional chemical synthesis processes, to afford a series of three and/or four-pharmacophoric-motif conjugates 8a,b, 11, 13, 16, 17, 19 and 20 in good yields. The newly synthesized compounds were characterized by IR, NMR, (13)C-NMR, MS and elemental analyses. Finally the synthesized compounds have been screened for their biological activity whereupon they exhibited remarkable antimicrobial activity on different classes of bacteria and the fungus.