P-Xylene → Benzene, 2-bromo-1,4-dimethyl-

Participants

Reaction Steps

p-Xylene (934.4 g; 8.8 mol) and Fe powder (16 g) were placed in the reaction vessel and about 20 ml of bromine were slowly added dropwise. The commencement of the reaction (after about 10 minutes) could be recognized by gas evolution. After the reaction had begun, the remaining bromine (total: 1278.4 g; 8.0 mol) was added dropwise at RT, with water bath cooling (4 hours). The mixture was stirred further for 2 hours at RT. The slightly brownish reaction solution was filtered off and stirred first with water, and then with 480 ml of saturated aqueous Na2SO3 solution, subsequently shaken once with dilute aqueous NaOH and twice with H2O; the organic phase (clear and colorless) was dried over MgSO4, filtered and purified by being vacuum-distilled twice (diaphragm pump/oil bath, about 100-120° C./60 cm column).

Provenance & Evidence