Synthesis of 4-allyl- and 4-benzyl-2,6-dimethylbromobenzene from 2,6-xylidine

-Allyl-2,6-xylidine was unchanged when heated alone, but rearranged to 4-allyl-2,6-xylidine with zinc chloride in refluxing xylene. When the hydrochloride was heated alone, the principal reaction was dissociation to allyl chloride and xylidine, and only a trace of 4-allyl compound was formed. In contrast, -benzyl-2,6-xylidine did not rearrange in the presence of zinc chloride but the required 4-benzyl-2,6-xylidine was obtained by direct benzylation of 2,6-xylidine. The 4-allyl-and 4-benzyl-2,6-xylidines were converted smoothly to the corresponding bromobenzenes by the Sandmeyer reaction.