Photochemical reactions of NN-dialkyl-α-thioxoamides

Abstract

NN-Di-isopropyl- and NN-di-s-butyl-α-phenylthioxoacetamide, (1a) and (1b), undergo γ-hydrogen abstraction on irradiation in methanol to give the corresponding β-lactams (2a) and (2b), respectively. Irradiation of NN-diethylthioxoamide (1d) yields the dimeric product, the disulphide (3d), while photolysis of (1d) in a viscous medium gave the thiazolidinone (6d)via γ-hydrogen abstraction. These reactions are presumed to proceed from the upper excited states. The selective γ-hydrogen abstraction is explicable in terms of an electron-transfer mechanism.