Abstract
Condensation-cyclization of hydrazine with 4-methoxycarbonylbenzo [g]quinolinequinone or its corresponding carboxylic acid afforded 7-hydrazino-2H-benzo[2,3-g]pyridazino [4,5-d,e]-quinolin-3-one. Starting with the 9-hydroxy derivative, a similar double condensation of the nucleophile was observed, whereas its 6-hydroxylated regioisomer gave 2H-benzo[2,3-g]pyridazino[3,5-d,e]quinolin-3,7-dione.