... (5) For synthesis of 9-acridones, see: (a) Gagan, JMF In Acridines, The Chemistry of Heterocyclic ... The organic phase was dried (Na2S04) and concentrated under reduced pressure to leave the crude chloro malonates I in 60430% yield. ... J. Org. Chem., Vol. 53, No. 4, 1988 881 ...