Colourless bromo-phenol prepn. - by reacting opt. halogenated phenol with hydrogen peroxide in conc. aq. hydrogen bromide contg. hydrochloric acid and/or hydrofluoric acid

摘要

In the parent patent, pure bromophenols (I) are prepd. by reacting opt. halogenated phenols with H2O2 in an aq. HBr soln.. In the addn., the aq. HBr used in reaction contains 0.1-20 wt.% HCl and/or HF, as contaminants, in addn. to 25-62 wt.% HBr. Colourless (I) are obtd. in 99% yield, using contaminated HBr without need for cumbersome purification.