Rapid and green synthesis of tetrahydrobenzo[b]pyran derivatives using reusable [EMIM][OH] ionic liquid

Ethyl methyl imidazolium hydroxide [EMIM][OH] ionic liquid catalyzed green protocol was developed for efficient and one-pot three-component condensation of various aromatic aldehydes, malononitrile, and dimedone under microwave irradiation for the synthesis of tetrahydrobenzo[b]pyran derivatives. The reaction proceeds in a short time period to afford moderate to excellent yield of products. The ionic liquid was recycled and reused for multiple time significantly, without a change in its catalytic efficiency.