Amberlite IRA-400 (OH-) as a Catalyst in the Preparation of 4H-Benzo[b]pyrans in Aqueous Media.

A quaternary ammonium hydroxide-type of anion exchange resin (Amberlite IRA-400) was found to be an effective and reusable catalyst for the synthesis of various 4H-benzo[b]pyran derivatives via a one-pot, three-component condensation in aqueous media. Short reaction time, easy and quick isolation of the products, environmentally friendly procedure, excellent chemoselectivity, and excellent yields are the main advantages of this procedure. [ABSTRACT FROM AUTHOR]