85223-93-4

95-87-4

85223-93-4

A solution of tetrabutylammonium tribromide (19.9 g, 41.39 mmol) in chloroform (150 mL) was slowly added dropwise to a stirred suspension of 2,5-dimethylphenol (5.0 g, 40.9 mmol) in water (150 mL) at room temperature. The reaction mixture was stirred continuously for 2 hours at room temperature. Upon completion of the reaction, the organic layer was separated and dried with anhydrous sodium sulfate. The dried organic phase was filtered and concentrated under reduced pressure to remove the solvent. The resulting crude product was purified by silica gel column chromatography with the eluent being a hexane-ethyl acetate solvent mixture of 1:5, v/v, to give 2,5-dimethyl-4-bromophenol as a brown solid (6.2 g, 76% yield). The structure of the product was confirmed by 1H NMR (300 MHz, DMSO-d6): δ 9.47 (s, 1H), 7.24 (s, 1H), 6.74 (s, 1H), 2.21 (s, 3H), 2.07 (s, 3H). Thin-layer chromatography (TLC) analysis conditions: Uniplate silica gel plates, 250 µm thickness; mobile phase was hexane-ethyl acetate in 9:1 volume ratio; Rf value was 0.52.