The photochemical reaction of 3,4,5-triphenyl-4-oxazolin-2-one.
Irradiation of 3,4,5-triphenyl-4-oxazolin-2-one (1) in benzene, under nitrogen, with or without iodine gave benzanilide and phenanthroxazolinone 2. However, in the presence of oxygen 1 was photochemically converted to benzanilide, benzoic acid, and benzamidobenzophenones. This photooxygenation is interpreted by the pathway proceeding via an initial attack of singlet oxygen to 1 forming a dioxetane, followed by ring cleavage to yield N,N-dibenzoylaniline (6) which gives final products.