Synthesis of coumarin (2H-chromen-2-ones) derivatives

Enzymes are biological catalysts that are believed to be the cornerstones of life. The combined enzyme in nanoformats is called nanobiocatalyst. Nanofibers, hybrid nanoflowers, mesoporous/nanoporous carriers, carbon nanotubes, magnetic or non-magnetic nanoparticles, and nanocomposites as support carriers can be used for the immobilization of different enzymes to develop nanobiocatalysts with potential activity and stability characteristics.1 Coumarin and its derivatives are important compounds due to their presence in naturally occurring aromatic products found in plants and cinnamon flavoured foods.2 These compound have applications including antibacterial, anti-inflammatory, anti oxidant, anticoagulant, anticancer and anti-HIV.3 Coumarins can be synthesized by various methods such as Perkin, Pechmann, Knoevenagel, Reformatsky and Witting reactions.4 Here in, we initially synthesized Fe3O4@SiO2 and then aminated, eventually, immobilized the trypsin onto it. We have demonstrated an efficient protocol for the synthesis of coumarin derivatives 3 via Pechmann condensation reactions of phenols 1 and β-ketoester 2 using as magnetically separable nanobiocatalyst as reusable catalyst in aqueous ethanol (Fig. 1). The purified products were characterized by spectral methods: FT-IR, 1H-NMR, 13C-NMR. The nanobiocatalyst was separated simply by using an external magnet, after completion of the reaction and recycled up to several times without loss of catalytic activity.

کلیدواژه ها:

Nanobiocatalysts ، Phenols ، Pechmann condensation ، Coumarins