Hydrogen Bromide → (2,6-Dichloro-4-methoxybenzyl)(triphenyl)phosphonium bromide

Participants

Reaction Steps

A solution of (2,6-dichloro-4-methoxyphenyl)methanol (3.00 g, 14.5 mmol) in 30% HBr in acetic acid (45 mL) was stirred at 20° C. for 3 h, then poured onto ice-water (120 mL) and extracted with pentane (6×100 mL). The extracts were washed with water (3×200 mL), backextracting with pentane (100 mL). Removal of the solvent gave the crude bromide as white crystals, which was immediately redissolved in benzene (80 mL) and treated with triphenylphosphine (5.70 g, 21.7 mmol), stirring at reflux for 15 h. After cooling, the precipitate was collected by filtration, washing thoroughly with dry benzene, then pentane, and dried under vacuum at 50° C. to give the phosphonium salt (521) as a white solid (7.75 g, 100%), mp (CH2Cl2/benzene) 188–190° C. 1H NMR (CDC3) δ 7.83–7.60 (m, 15H), 6.74 (s, 2H), 5.37 (d, J=13.5 Hz, 2H), 3.76 (s, 3H). Found: C, 58.40; H, 4.35. C26H22BrCl2OP requires C, 58.67; H, 4.17.

Provenance & Evidence