Bromine cyanide, decomposition

Benzofuroxan may be obtained by oxidation of o-quinone dioxime. The first benzofuroxan derivative, 1,2-naphthofuroxan, was obtained by this method. Suitable oxidizing agents include alkaline ferri-cyanide, bromine water, chlorine, and nitric acid. The method is of practical value only when the o-quinone or its monooxime (o-nitrosophenol) is readily available, and since this is not generally the case, other routes, e.g., the oxidation of o-nitroanilines and the thermal decomposition of o-nitrophenyl azides/ are more commonly used. 

If the /7-position of the amine is blocked by methoxy, methyl, chlorine or bromine groups, the species is stable with respect to dimerisation and higher anodic potentials are required for its further oxidation. However, further decomposition of the tri /7-anisylamine radical cation occurs in the presence of any traces of cyanide ion present in the acetonitrile solution. Primary aromatic amines, like phenols, tend to polymerise upon oxidation unless the o and p positions are blocked. 2,4,6-tri-t-butylaniline in acetonitrile solution yields a fairly stable radical cation which in the presence of water forms 3,5-di-f-butyl-4-amino-2,5-cyclohexadienone. ° ... 

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