POLYHALOGENO-AROMATIC COMPOUNDS .8. REACTIONS OF HEXABROMOBENZENE WITH NUCLEOPHILES

Hexabromobenzene unlike its chloro- or fluoro-analogues undergoes protodebromination when treated with sodium methoxide in methanol and ethyl methyl ketone to give a mixture of tetrabromobenzenes. With piperidine or ethanolic ammonia debromination and some nucleophilic substitution occurs. Hydrazine gives only 1,2,3,4-tetrabromobenzene while cyclohexylamine or sodium methoxide in pyridine give the corresponding substitution products. Attempts have been made to rationalise these results.