The synthesis of tetrahydrobenzo[b]pyran derivatives is significant because of their important diuretic, spasmolytic, anti-cancer, anti-coagulant and anti-anaphylactic properties.1 2-amino- 4H-pyran derivatives can be broadly used as photoactive materials.2 Furthermore, substituted 4H-pyrans are identified as units in the structure of some natural products.3, 4 A simple, clean and eco-friendly benign three-component protocol for the synthesis of tetrahydrobenzo[b]pyran derivatives via the condensation reaction of dimedone with various arylaldehydes and malononitrile in the presence of nano structure molten salt namely 1- methylimidazolium tricyanomethanide as green mild and efficient catalyst in the absence of any organic solvent under ambient temperature will be discussed