P. Shanmugasundaram et Vt. Ramakrishnan, SYNTHESIS OF HYDRO-BISBENZO[1,2-A-1',2'-J]ACRIDINES, Indian journal of chemistry. Sect. B: organic chemistry, including medical chemistry, 36(1), 1997, pp. 17-20
Hexahydroacridinediones 1,5-7 are oxidised to tetrahydroacridinediones
2,8-10 by active MnO2 in chloroform. Formylation of tetrahydroacridin
ediones, followed by Michael addition with MVK and cyclisation furnish
es the hydrobisbenzoacridines 18-20.