Dibromo-2,6-dimethylphenol

Dibromo-3,6-dimethylphenol (X = H) upon nitration in acetic add gave the cydohexenone shown while 2,4,5-tribromo-3,6-dimethylphenol (X = Br) afforded the bromo analogue. By aqueous nitratbn of either compound a ring-contracted product was obtained which also resulted through Favorsky rearrangement from the tribromo compound by treatment with aqueous sodium carbonate (ref. 54). 

With 3-methylphenol (meto-cresol), around 8 % of dibromo products result when one equivalent of brominating agent is used, and this rises to 23 % of dibromo products on attempted monobromination of 3,5-dimethylphenol with 1 molar equivalent of resin. Nevertheless, the good yields of products obtained from the mono-substituted phenols tried demonstrate that this is a powerful new synthetic method for the organic chemist. 

Bromination of mesitol with excess bromine produced 4-bromomethyl-3,5-dibromo-2,6-dimethylphenol as a major product which on hydrolysis produced 4-hydroxymethyl-3,5-dibromo-2,6-dimethylphenol (8). Both 4-bromomethyl- and 4-hydroxymethyl-3,5-dibromo-2,6-dimethylphenol are excellent alkylating agents. With or without catalyst, in a solvent or without solvent, they react readily with other phenolics to form alkylation products Q2). The following equations exemplify these reactions ... 

Other Names Phenol, 4,4 -(3H-2,l-benzoxathiol-3-ylidene) w[3-bromo-2,5-dimethyl-, S,S-dioxide 3H-2,l-Benzoxalhiole, phenol deriv. 3,3 -Dibromo-p-xylenolsulfophthalein 4,4 -(3H-2,l-Benzox-alhiol-3-ylidene) w[3-bromo-2,5-dimethylphenol] S,S-dioxide Bromoxylenol blue Bromxylenol blue... 

Polymerization of 3f4-dibromo-2,5-dimethylphenol (I) provided a route to polymer in which the bromine was only on the aromatic rings and not on the methyl groups (reaction 1). The reaction was found to proceed under conditions. similar to the reaction described by Staffin and Price for the polymerization of 4-bromo-2,6-dimethylphenol, III (reaction 2). Poly(3-bromo-... 

The nmr and ir spectra of the products from direct bromination showed that only ring bromination had occurred euid that there was no methyl group bromination. The spectra were almost identical to the spectra of the corresponding homopolymers cind copolymers from combinations of 2,6-dimethylphenol, 3,4-dibromo-2,6-dimethylphenol and 3,4,5-tribromo-2,6-dimethylphenol. A detailed description of the spectra of these bromlnated polymers is presented in the preceding paper. 

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