p-Toluenesulfonic acid monohydrate → HCID 21996962, compound

Participants

Reaction Steps

To a cold solution (−78° C.) of 99 mg (0.3 mmol) of 5-bromo-2-hydroxy-3′-methylbenzophenone (Compound L) in 5 mL of tetrahydrofuran (under a blanket of argon) was added 1.0 mL (3.0 mmol) of methyl magnesium chloride (3M in tetrahydrofuran). With the addition, the solution turned yellowish-orange in color. The −78° C. bath was removed and the solution was allowed to warm to ambient temperature and stirred for 2 hours. The reaction mixture was concentrated in vacuo, extracted between ethyl acetate and sat. NH4Cl (aq.) solution and the layers were separated. The organic phase was washed with water and brine, dried over MgSO4, filtered and concentrated in vacuo to give crude 4-bromo-2-[(1-m-tolyl-1-hydroxy)ethyl]phenol as a yellow oil. The crude alcohol was dissolved in 2 mL of toluene, placed under a blanket of argon and 5.9 mg of p-toluene sulfonic acid monohydrate was added. The resultant mixture was heated at 70° C. for 45 minutes, cooled to ambient temperature and purified by flash chromatography (silica, 5% ethyl acetate in hexane) to give the title compound as a clear, colorless oil.

Provenance & Evidence