1-Ethyl-3-Methylimidazolium Cyanoborohydride Catalyzed Solvent FreeMicrowave Assisted One Pot Multicomponent Synthesis of Tetrahydrobenzo[b]Pyran Derivatives

Abstract

: We present a facile and environmentally benign protocol for the synthesis of tetrahydrobenzo[b]pyran derivatives via multi-component condensation of dimedon, malononitrile and different aromatic aldehydes in 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 de-rived 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.