Reactions of 8-(Triphenylphosphoimino)quinoline with Aryl Aldehydes and Aryl Isocyanates: Formation of 2-Aryl-4H-imidazo[4,5,1-ij]quinolines and Related Systems

The reaction of 8-(triphenylphosphoimino)quinoline with aryl aldehydes gave 2-aryl-4H-imidazo[4,5,1-ij]quinolines. In the reaction, tandem aza-Wittig reaction and cyclization attended with hydride shift occurred. The reaction of 8-(triphenylphosphoimino)quinoline with aryl isocyanates gave 1,3-diaryl-1,2,3,9a-tetrahydro[1,3,5]triazolo[2',3':2,1;3',4'-a]imidazo[4,5,1-ij]quinolin-2-ones (11) and 2-(arylamino)imidazo[4,5,1-ij]quinolin-4(4H)-ones (12). The structures of 11a (Ar = Ph) and 12a (Ar = Ph) were confirmed by X-Ray structure analyses.