1969 年 27 巻 1 号 p. 51-58
7-Acetylamino-, benzoylamino- and tosylamino-3-phenylisocarbostyril have been synthesized from the corresponding isocoumarins and aqueous ammonia. In an aqueous solution of methylamine, 7-acetylamino-3-phenylisocoumarin (2a) was hydrolyzed into 4'-acetylaminodesoxybenzoin-2'-carboxylic acid. 7-Acetylamino-N-methyl-3-phenylisocarbostyril was obtained by heating (2a) with methylamine in ethanol in an autoclave at 100°C for 10 hrs. Similarly, N-ethyl, N-n-propyl, and N-n-butyl analogs were prepared. N-Phenyl-isocarbostyril derivative was formed only when (2a) was treated with aniline in the presence of boric acid for 5 hrs at 200210°C. By heating a mixture of (2a) and o-phenylenediamine in the presence of polyphosphoric acid for 2 hrs at 200220°C, 2-amino-6-phenylbenzimidazo [2, 1-a] -isoquinoline (5) was formed. When boric acid was used as a condensing agent, N- (o-aminophenyl) -isocarbostyril derivative, instead of (5), was obtained. 6- Phenylbenzimidazo [2, 1-a] -isoquinoline and acetylamino derivative of (5) were also prepared. Infrared, ultraviolet absorption and fluorescence spectra of these new compounds were measured and discussed.