Oxidation gives the aza-dienophile 4-phenyl-1,2,4-triazolinedione which is more reactive in cycloaddition reactions than tetracyanoethylene: J. Chem. Soc. (C), 1905 (1967); Angew. Chem. Int. Ed., 11, 715 (1972); Org. Prep. Proced. Int., 7, 251 (1975). Suitable oxidants include t-butyl hypochlorite: Org. Synth. Coll., 6, 936 (1988), or lead(IV) acetate: J. Org. Chem., 32, 330 (1967). The adducts can be cleaved to the hydrazo-compounds by hydrazine hydrate. Cu(II) oxidation provides a route to azoalkanes: Synthesis, 543 (1981). Reacts with enolizable ketones in the presence of TFA to give ɑ-urazyl ketones: J. Org. Chem., 55, 193 (1990), which may be oxidized to ɑ-diketones with t-butyl hypochlorite: J. Org. Chem., 55, 197 (1990). Review of use of azodicarbonyl compounds in synthesis: Adv. Het. Chem., 30, 1 (1982). 1,2,4-Triazolinediones form charge-transfer complexes with electron-rich aromatics, such as di- or trimethoxybenzenes: J. Org. Chem., 48, 1708 (1983).