2-Bromo-1-chloro-4-methoxymethyl-benzene synthesis

Yield:1079402-21-3 94%

Reaction Conditions:

Stage #1: 3-bromo-4-chloro-benzyl alcoholwith potassium hydroxide in 2-methyltetrahydrofuran at 20; for 0.5 h;
Stage #2: methyl iodide in 2-methyltetrahydrofuran at 20; for 19.0833 h;

Steps:

53

To a stirred solution of 4-chloro-3-bromophenyl-methanol (cited in Amgen patent WO03099776) (900 mg, 4.06 mmol) in 2-methyl-tetrahydrofuran (15 ml) was added potassium hydroxide (912 mg, 16.3 mmol) and the resulting suspension was stirred at room temperature for 30 minutes, lodomethane (1.01 ml, 4.00 mmol) was then added and the reaction was stirred for 16 hours at room temperature. LCMS indicated incomplete reaction. Potassium hydroxide (912 mg, 16.3 mmol) was added and the resulting mixture stirred for 5 minutes before adding further iodomethane (4.04 ml, 16 mmol) and stirring was continued for 3 hours at room temperature. Ethyl acetate (60 ml) and saturated brine solution (30 ml) were added and the layers were separated. The organic extract was further washed with saturated brine solution (2 x 30 ml) then dried over anhydrous MgSO₄ (s), filtered and evaporated in vacuo to afford the crude title compound as a yellow oil (901 mg, 94%).¹HNMR (CZ₆-DMSO): 3.40 (s, 3H), 4.21 (s, 2H), 5.50 (br s, 2H), 7.21 (dd, 1 H), 7.42 (d, 1 H), 7.60 (s, 1 H).

References:

WO2008/135826,2008,A2 Location in patent:Page/Page column 170