Synthesis of 4,10‐dihydro‐4,10‐dioxo‐1 H ‐[1]‐benzopyrano[3,2‐ b ]pyridine, 4,5‐Dihydro‐4,5‐dioxo‐1 H ‐[1]‐benzopyrano[2,3–6]pyridine and 1,5‐Dihydro‐1,5‐dioxo‐4 H ‐[1]‐benzopyrano[3,4‐ b ]pyridine derivatives from aminobenzopyrones

3‐Aminochromone and 3‐aminocoumarin were condensed with diethyl ethoxymethylenemalonate and with dimethyl acetylenedicarboxylate to give intermediates, which were thermally cyclized to give 4,10‐dihydro‐4,10‐dioxo‐l H ‐[1]‐benzopyrano[3,2‐ b ]pyridinecarboxylates and 1,5‐dihydro‐1,5‐dioxo‐4 H ‐[1]‐benzopyrano‐[3,4‐ b ]pyridinecarboxylates. 2‐Aminochromone was converted to 4,5‐dihydro‐4,5‐dioxo‐1 H ‐[1]‐benzopyrano‐[2,3‐ b ]pyridinecarboxylate via an intermediate condensation product with diethyl ethoxymethylenemalonate. These esters were hydrolyzed to the corresponding carboxylic acids (21, 30, 36, 50, and 60). Attempts to prepare 4,5‐dihydro‐4,5‐dioxo‐1 H ‐[1]‐benzopyrano[4,3‐ b ]pyridinecarboxylates from 4‐aminocoumarin were unsuccessful.