A convenient one pot synthesis of substituted 4-aminobenzopyrano[3,4-c]pyridinones

A new synthesis of substituted 4-aminobenzopyrano3,4-c]pyridinones was achieved in one pot by the condensation of an o-hydroxyaraldehyde and a cyclic or acylic methyl ketone in the presence of ammonium acetate in refluxing ethanol followed by the treatment of malononitrile and subsequent hydrolysis with hydrochloric acid in situ.