Precursor directed regioselective synthesis of partially reduced benzoeindene through oxidative cyclization and benzohquinolines

摘要

We have reported a simple, unprecedented base promoted synthesis of 7-substituted-1-(2-cyano-phenyl/ phenyl)-3-sec amino-4,5-dihydro-1H-benzeindene-1,2-dicarbonitriles by reaction of 2-oxo-4-sec amino-5,6-dihydro-2H-benzohchromene-3-carbonitriles and 2-cyanomethyl-benzonitrile/phenylacetonitrile under basic conditions at 100 degrees C. This reaction involves ring opening of 2-oxo-4-sec amino5,6-dihydro-2H-benzohchromene-3-carbonitrile by a carbanion generated in situ from 2-cyanomethylbenzonitrile/phenyl-acetonitrile followed by oxidative cyclization to afford the desired product. Alternatively, reaction of 6-aryl-4-sec amino-2H-pyran-2-one-3-carbonitriles and 2-cyanomethyl-benzonitrile under basic conditions provides functionalized benzohquinolines. The structure of the synthesized compound was confirmed by single crystal X-ray.