5-22-04-00433 (Beilstein Handbook Reference) 983-36-8 9aH-quinolizine-1,2,3,4-tetracarboxylic acid, 7,9-dimethyl-, tetramethyl ester BRN 0366484 NSC 529030 Tetramethyl 7,9-dimethyl-9aH-quinolizine-1,2,3,4-tetracarboxylate