Photolysis of acetyl esters of 2,2′-dinitrodiphenyl-carbinols in protic and aprotic solvents

Irradiation ofacetyl esters of 2,2′-dinitrodiphenyl-carbinols (1a-d) in aprotic medium like 2-propanol yielded dibenzol c,f]-1,2]diazepin-11-one-5-oxides (5a-d) as the major product. Dibenzoic,f]-1,2]diazepin-11-one (2a-d), 2,2′-dinitrobenzophenones (3a-d), 2-amino-2′-nitrobenzophenones (4a-d), and N-hydroxyacridones (6a-d) were also formed in varying amounts. Irradiation of 1a-d in an aprotic medium like benzene yielded the above products along with benzisoxazoles (7a-d) also. When triethylamine was used as the solvent the major product obtained was N-hydroxyacridones (6a-d). Plausible mechanisms for the formation of the products are discussed