In SbF5-HF, reaction of bromine with 2, 6-dimethylphenol gives the meta bromo compound 1b which is further halogenated to 3, 4-dibromo-2, 6-dimethylphenol 1c. In the same conditions ether 2a yields successively 2b and 2d. Meta bromination of compounds 1a, 2a, 2b implies electrophilic attack on the O-protonated substrate, whereas reaction of the neutral phenol 1b leads to the p-bromoderivative 1c. All products are obtained in excellent yields ( ...
