Al(H2PO4)3 as an efficient and recyclable catalyst for the one-pot synthesis of naphthopyranopyrimidines

Abstract

An efficient one-pot protocol has been developed for the synthesis of naphthopyranopyrimidine derivatives via a three-component reaction of aromatic aldehydes, β-naphthol and 6-amino-1,3-dimethyl uracil in the presence of Al(H₂PO₄)₃ as a catalyst under solvent-free conditions at 110 °C. The presented methodology offers several advantages such as simplicity of operation, easy workup, good to high yields, short reaction times, inexpensive and readily available starting materials and catalyst. Furthermore, the catalyst can be reused several times without any significant loss of activity.