One-Pot Green Synthesis of Pyridine-2-carbaldehyde based Chalcones under Solvent-Free Condition using Mesoporous MCM-41 Materials and their Antimicrobial Activities

Abstract

A simplistic one-pot synthetic protocol was performed using aromatic ketones (1a-e) and substituted pyridine-2-carbaldehydes (2a-e) to obtain various substituted chalcones (3a-e). The synthesis was catalyzed by various metal incorporated (Mn, Al) and acid functionalized (H2SO4, H3PW12O40) mesoporous MCM-41 materials, under solvent free conditions. Using pyridine-2-carbaldehyde (2a), its analogs viz., 4-methoxy (2b), 4-chloro (2c), 4-hydroxy (2d) and 4-nitro (2e) pyridine-2-carbaldehydes were synthesized separately, in order to use these precursors for the formation of the organic derivatives 3b to 3e. Their structural features were characterized by using 1H NMR, 13C NMR and mass spectral techniques. Both the acid functionalized MCM-41 were almost equal in their catalytic performance, whereas among the Mn+-MCM-41 [Mn+ = Mn/Al], the Al incorporated material has shown slightly higher catalytic performance. The antimicrobial activities of the derivatives (3a-e), was investigated on the selected microorganisms, using standard procedures. In these studies, except the compound 3e, remaining compounds have displayed superior biological activity.