Abstract
We present a facile and environmentally benign protocol for the synthesis of tetrahydrobenzo[ b]pyran derivatives via multicomponent condensation of dimedon, malononitrile and different aromatic aldehydes in the presence of 1-ethyl-3-methylimidazolium cyanoborohydride ([EMIm][BH3CN]) as catalyst under microwave irradiation. The one-pot synthesis, facile solvent-free condition and good isolated yield illustrate the utility of this green approach. The structural features are derived using analytical tools, including Fourier Transform Infrared Spectroscopy (FT‐IR) and 1H and 13C Nuclear Magnetic Resonance (NMR) Spectroscopy. Electronic synthesis of tetrahydrobenzo[b]pyran derivatives by using catalytic action of 1-ethyl-3-methylimidazolium cyanoborohydride has been used to obtain maximum yield.
Keywords: Tetrahydrobenzo[b]pyran, microwave irradiation, solvent free, ionic liquid, FT-IR, TLC.
Graphical Abstract
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