Hydrogen Bromide → Benzene, 2-bromo-1,4-dimethyl-

Participants

Reaction Steps

This experiment was carried out in two successive steps. In the first stage the total p-xylene was divided into two parts and one-half of the p-xylene was added to the reaction vessel with the catalyst. The other half of the p-xylene and the bromine were then added simultaneously but in separate streams to the flask while maintaining the temperature of the reacting mixture at 20°-25°C. When the reaction was completed as evidenced by no further hydrogen bromide evolution, the resulting mixture was distilled. An initial fraction of monobromo-p-xylene was taken off at 75°-103° (9mm). The 2,5-dibromo-p-xylene was recovered by distillation at 122°-126° (10 mm) as a water-white liquid which solidified to a white, fused, crystalline mass.

Provenance & Evidence