Potassium phthalimide catalyzed efficient synthesis of 2-Amino-3-phenylsulfonyl-4H-chromenes under Solvent-Free Conditions

An efficient and eco-friendly protocol for the preparation of 2-amino-3-phenylsulfonyl-4H-chromenes employing a three component, one-pot condensation reaction between aromatic aldehydes, phenylsulphonylacetonitrile and 1-naphthol has been developed. The reaction of 1-naphthol with phenylsulphonylacetonitrile and various aromatic aldehydes was carried under solvent-free conditions using 10 mol% of potassium phthalimide as a catalyst to give the corresponding products in good to excellent yields. It was also found that potassium phthalimide can be recycled at least four times without loss of activity. General applicability, operational simplicity, mild reaction conditions, short reaction time, non-toxic, inexpensive and recyclable catalyst, and solvent-free conditions are the advantages of the present procedure.