co(no3)2·6h2o as a powerful and reusable catalyst for the synthesis of phenylbenzo[g]chromenes

An efficient and easy protocol for the one-pot three-component synthesis of phenylbenzo[g]chromenes was developed. the synthesis was achieved by the reaction of aromatic aldehydes, meldrum’s acid, and 2-hydroxynaphthalene-1,4-dione in the presence of catalytic amount of co(no3)2·6h2o at room temperature. the important advantages of this procedure are short reaction times, high yields, easy work-up, reusable catalyst, and no need to column chromatography.