Abstract

Polyethylene glycol is found to be a nontoxic and recyclable reaction medium for the microwave-assisted, multi-component one-pot reactions of aromatic aldehydes with ethyl-2-cyanoacetate and 1,3-cyclohexanedione or 5,5- dimethyl-1,3-cyclohexanedione in the presence of piperidine. This environmentally friendly microwave protocol offers ease of operation and enables recyclability of reaction medium and synthesis of a variety of substituted tetrahydrobenzo[b]pyran derivatives. It is an efficient, promising, and green synthetic strategy to construct tetrahydrobenzo[b]pyran skeleton.

Keywords: Microwave assisted, multi-component, one-pot reaction, PEG-400, Tetrahydrobenzo[b]pyrans, Polyethylene glycol, nontoxic, recyclable reaction, green synthetic strategy, solvent-free syntheses, organic reactions, pharmacological properties