Condensation of 4-azafluorenone and 9-phenacylidene-4-azafluorene with acetophenone. Synthesis of 3′-oxo-spiro-[4-azafluorene-9,1′-indane]

Condensation of 4-azafluorenone and 9-phenacylidene-4-azafluorene with acetophenone leads to the formation of 9,9-diphenacyl-4-azafluorene and 9-(1,2-dibenzoylethylidene)-4-azafluorene. The structures of these products were confirmed based on their spectral and chemical data. The conversion of 9,9-diphenacyl-4-azafluorene to 3-oxo-spiro-[4-azafluorene-9,1-indane] represents a novel method for the preparation of this heterocycle.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1239–1242, September, 1988.