Methanol → 4-(Bromomethyl)-3,5-dichloropyridine

Participants

Reaction Conditions

Reaction Steps

A cold (0° C.) solution of 4-hydroxymethyl-3,5-dichloropyridine (3.0 g) and N-bromosuccinimide (6.1 g) in dry dimethylformamide (100 mL) is treated with triphenylphosphine (8.9 g), portionwise, during 5 minutes. The resulting red solution is stirred at 0° C. for 45 minutes, and then treated with methanol (5 mL), followed by water (300 mL). The mixture is extracted with diethyl ether (4×200 mL), the combined organic washings dried over sodium sulfate, and the solvent removed under reduced pressure. The resulting residue is chromatographed on silica gel, eluting with a mixture of diethyl ether and pentane (1:2 v/v), to give 4-bromomethyl-3,5-dichloropyridine (3 g), in the form of an off-white solid, m.p. 40°-44° C.

Provenance & Evidence