Photochemistry of 2,2'-dinitrodiphenylmethanes. II. Irradiation of 5,5'-dimethyl- 2,2'-dinitrodiphenylmethanes in neutral, acidic and alkaline media

Abstract

Photolysis of 5,5'-dimethyl-2,2'-dinitrodiphenylmethanes(1)in propan-2-ol yielded 2,9-dimethyl-11 H-dibenzo[c,f][1,2]diazepin-11-one 5-oxides(2) as the major product. 5-Methyl-3-(5'-methyl-2'- nitrophenyl)-2,1-benzisoxazoles (3), 2,9-dimethyldibenzo[c,f][1,2]diazepin-11-ones (4),2,2'-dinitro-tenzophenones (5), acridinones (6), N-hydroxyacridinones (7), dibenzo[c,f][1,2]diazepin-11-one 5,6-dioxide (8)and 2,2'-dinitrosobenzophenone(9)were also formed in varying amounts. Irradiation of (1) in acidic ethanol afforded benzisoxazoles (3) as the major product. In benzene medium, the major photoproduct of (1) was 2,2'-dinitrobenzophenones (5). Irradiation of (1) in triethylamine afforded dibenzo[c,f][1,2]diazepines (12) also in addition to the other products. A plausible mechanism to account for the formation of various products in these photoreactions is discussed.