Cyanoethylation of substituted 4-azafluorenes. Synthesis of spiro-[4-azafluorene-9-cyclopentenes]

Cyanoethylation of 9-phenacyl(β-hydroxy-β-phenylethyl-, or acetamido)-4-azafluorenes under conditions of the Michael reaction occurs regioselectively at position 9. 1-Amino-4-azafluorene under these conditions forms 1-[N,N-di-(β-cyanoethyl)amino)]-(9-β-cyanoethyl)-4-azafluorene. The cyclization of 9-(β-cyanoethyl)-9-phenacyl-4-azafluorene has been carried out into 1′-cyano-2′-phenylspiro[4-aza-fluorene-9,4′- cyclopentene and 1′-imino-2′-hydroxybenzylidenespiro[4-azafluorene- 9.3′-cyclopentane]-substituted in the five-membered fragment. © 2006 Springer Science+Business Media, Inc