Nano triethanolammonium trichloroacetate as new catalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives

Tetrahydrobenzo[b]pyrans are an important class of heterocyclic scaffolds in the field of pharmaceuticals. These compounds are widely used as anti-coagulant, diuretic, spasmolytic, anticancer and anti-anaphylactic agents (1-3).Numerous methods have been reported for the synthesis of tetrahydrobenzo[b]pyrans.Nano triethanolammonium trichloroacetate [TEATCA] was used as new catalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives under solvent- free conditions at 60 °C.In a typical experimental procedure, a mixture of aromatic aldehyde, malononitrile,dimedone under solvent-free conditions at 60°C, was stirred in the presence of a catalytic amount of TEATCA to afford the tetrahydrobenzo[b]pyranin high yields (Figure 1). Use of nontoxic reaction components, short reaction times,easy work-up and high yields are some important advantages of this method.