Chemistry of Heterocyclic Compounds. Латвийский институт органического синтеза Латвийской академии наук / Springer New York Consultants Bureau. Vol. 8. 1974. P. 604-606
3-Methyl-9,9-di(β-cyanoethyl)-2-azafluorene was obtained from 3-methyl-2-azafluorene via the Michael reaction and was converted to the dibasic acid and its diester. Dieckmann condensation of the latter and subsequent hydrolysis gave 3-methyl-4′-oxospiro(2-azafluorene-9,1′-cyclohexane). © 1974 Consultants Bureau, a division of Plenum Publishing Corporation.