Metabromation du dimethyl-2,6 phenol et de son ether methylique en milieu superacide

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 (> 85%).