2,6-dimethylanisole (synthesis)
N-bromosuccinimide
benzoylperoxide

2,6-Dimethylanisole (4.08 g, 30 mmol) was dissolved in CCl₄ (250 ml) along with benzoyl peroxide (10 mg).  N-Bromosuccinimide (21.36 g, 120 mmol) was added and the mixture was heated at reflux for 6 hours while being irradiated with a 250 W light-bulb.  The reaction was allowed to cool and was then filtered to give a yellow solution.  This solution was reduced in vacuo to give 2,6-bis(dibromomethyl)anisole as a pale yellow solid (13.42g, 99%).  A sample was recrystallised from hexane for characterisation.

mp 102-104 ^oC (ref 100-102 ^oC); δ_H (200MHz, CDCl3) 7.91 (2H, d, J 8.0, m-CH), 7.37 (1H, t, J 8.0, p-CH), 7.02 (2H, s, CHBr₂), 3.96 (3H, s, OCH₃).

B. L. Feringa and O. J. Gelling, J. Am. Chem. Soc., 1990, 112, 7599-7604.