Pyrazine chemistry. Part VII. Oxidations of piperazine-2,5-diones and derivatives

A solution of sulphur in dimethylformamide can act as an oxidant of certain N-blocked piperazine-2,5-dione derivatives, resulting in net dehydrogenation. The action of lead tetra-acetate on some representative derivatives of the title compounds has also been investigated, and affords acetoxylated products.