WALLACH REARRANGEMENT OF UNSYMMETRICALLY SUBSTITUTED AZOXYBENZENES AND OXIDATION OF AZO DERIVATIVES

The Wallach rearrangement of 3-chloro-3′-methyl- and 3-methyl-3′-nitro-azoxybenzene gave rise to the corresponding 4′-hydroxyazo derivatives with the hydroxyl group attached to the benzene ring adjacent to the trivalent nitrogen bridge, while 2,2′,5,5′-tetrachloro-4′-nitro- and 2′-nitro-4,4′,5,5′-tetrachloro-azoxybenzene were hydroxylated in the ortho and para positions respectively on the ring adjacent to the pentavalent nitrogen bridge.Oxidation of 3-methyl-3′-nitro-and 3-chloro-3′-methyl-azobenzene gave rise to the corresponding α-isomers, which was proved by the bromination and reduction products.The ultraviolet and visible absorption spectra of the unsymmetrically and symmetrically substituted azo- and azoxy-benzenes prepared have been recorded and briefly discussed.