Green and Efficient One-Pot Synthesis of 2-Amino-3-phenylsulphonyl-4H-chromenes under Solvent-Free Conditions

A green and convenient method for the synthesis of 2-amino-3-phenylsulphonyl-4H-chromenes by a one-pot three-component condensation of 1-naphthol, phenylsulphonylacetonitrile and aromatic aldehydes under solvent-free conditions using potassium phosphate tribasic trihydrate as an efficient catalyst is described. The reaction of 1-naphthol with phenylsulphonylacetonitrile and various aromatic aldehydes was carried out under solvent-free conditions at 100 °C using 10 mol% of potassium phosphate tribasic trihydrate as a catalyst. The results show that aromatic aldehydes containing electron-donating groups or electron-withdrawing groups could react smoothly to give the corresponding products in good to excellent yields. It was also found that potassium phosphate tribasic trihydrate can be recycled at least four times without loss of activity. High yields, short reaction times, ease of handling, cheap and reusable catalyst, mild and environmentally begin reaction conditions are the advantages of this procedure.