Cyano esters and malononitriles. IV. Cyano(fluorenyl)acetohydrazides and fluorenylpyrazolones

Abstract

Cyano(fluoren-9-yl)acetohydrazides cyclize readily under acid or basic conditions to give 3-amino-4-(9-substituted fluoren-9-yl)pyrazol-5(4H)- ones (3). Upon thermolysis of the hydrazides the pyrazolones and/or dimeric products are produced.    The cyanoacetohydrazides condense with phthalic anhydride to give the 2-(fluoren-9-yl)-N-phthalimidoacetamides(7), whereas, with succinic anhydride, the open-chain compounds (10) are obtained which upon thermolysis afford the dimeric compounds (6). The acetamides (7) undergo unusual reductive cleavage with sodium borohydride affording the fluorenylpyrazolones (3). Electronic, infrared and N.M.R. spectra of the products are discussed.