Hydrochloric Acid → 4-bromo-2-(chloromethyl)-1-methylbenzene

Participants

Reaction Conditions

Reaction Steps

To a mixture of 80.9 g (0.406 mol) of 5-bromo-2-methylbenzaldehyde and 7.80 g (0.206 mol) of NaBH4 in 300 ml of THF 200 ml of methanol was added dropwise by vigorous stirring for 5 h at 0-5° C. This mixture was stirred overnight at room temperature and then added to 1 liter of cold water. The resulting mixture was acidified by 2 M HCl to pH˜1, and the formed (5-bromo-2-methylphenyl)methanol was extracted with 3×250 ml of dichloromethane. The combined organic extract was dried over Na2SO4 and evaporated to dryness. To the residue dissolved in 450 ml of dichloromethane 37 ml of SOCl2 was added dropwise at +5° C. The resulting solution was stirred overnight at room temperature, evaporated to dryness, the residue was dissolved in 500 ml CH2Cl2, and the obtained solution was washed with 500 ml of water. The organic layer was separated, the aqueous layer was additionally extracted with 2×100 ml of dichloromethane. The combined organic extract was passed through a short pad of silica gel 60 (40-63 um), the filtrate was evaporated to dryness, and the residue was dried in vacuum to yield 5-bromo-2-methylbenzyl chloride as a slightly yellowish liquid which was further used without an additional purification.

Provenance & Evidence