Vinyliminophosphorane-mediated preparation of 2-arylquinoline and 4-aryl-1-azaanthraquinone derivatives. X-Ray crystal structure of 1,2-dihydro-3H-indazolo[2,3-a]quinolin-4-one

Article abstract of DOI:10.1016/0040-4020(94)01005-K

The reaction of the iminophosphorane derived from 3-azidocyclohexan-2-enone with substituted cinnamyl aldehydes affords 2-aryl-tetrahydroquinoline derivatives, which are easily converted into 2-arylquinolones. By contrast, iminophosphorane derived from 2-azidocyclohex-2-enone reacts only with α,β-unsaturated aldehydes without substituent at β-position to give 5,6-dihydro-8(7H)quinolinones. The iminophosphorane derived from 2-azido-1,4-naphthoquinone reacts with substituted cinnamyl aldehydes providing directly 4-aryl-1-azaanthraquinones. The crystal and molecular structure of 1,2-dihydro-3H-indazolo[2,3-a]quinolin-4-ono has been solved by X-Ray analysis.