Photolyse des 3‐Phenyl‐2, 1‐benzisoxazols und einiger seiner Derivate in Salzsäure bzw. Schwefelsäure

Photolysis of 3‐phenyl‐2,1‐benzisoxazole and some derivates in hydrochloric and sulfuric acid The photolysis of 3‐phenylanthranils (3‐phenyl‐2, 1‐benzisoxazoles) in conc. hydrochloric or sulfuric acid leads to the formation of 5‐substituted 2‐amino‐benzophenones wherein the 5‐substituent is the anion of the acid employed. 5‐Halo‐substituted 3‐phenylanthranils, however, show a differing reaction pattern in the two acids. Whereas 2‐amino‐3, 5‐dihalo‐benzophenones are obtained when photolysis is effected in conc. hydrochloric acid, irradiation in sulfuric acid causes the hydroxy group to substitute the halogen which migrates to the 4‐position of the 2, 1‐benzisoxazole to yield 2‐amino‐5‐hydroxy‐6‐halo‐benzophenones. A similar behaviour in sulfuric acid is also observed with 5, 7‐dichloro‐3‐phenylanthranil. When the 5‐position of the anthranil is blocked by a phenyl group, irradiation in conc. hydrochloric acid leads to entry of the halogen mainly in this 5‐phenyl substituent, as can be expected from mesomeric structures. The reaction mechanisms for the photolytic behaviour of 3‐phenylanthranils in both conc. hydrochloric and sulfuric acid is discussed.