N-aryl-C-nitroso-imines
Abstract
Reaction of 4-chlorophenyl-SS-dimethylsulphimide (1) with ethyl cyanoformate N-oxide, or oxidation of the amidoxime (6) with lead tetra-acetate, gives the nitroso-imine (4), which cyclises spontaneously to the 1,2,4-benzoxadiazine (3), but which can be reversibly intercepted in a Diels–Alder reaction with thebaine.