Boron trifluoride etherate → 4-Chloro-2-isopropylphenol

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Reaction Steps

To a −10° C. solution of 4-chloro-2-(hydroxypropan-2-yl)phenol (6.00 g, 32.15 mmol) in 100 mL of methylene chloride add triethylsilane (31.0 mL, 194.08 mmol) and boron trifluoride diethyl etherate (66 mL, 520.82 mmol) dropwise over a period of 10 minutes. Keep the reaction mixture cold and stir for an additional hour before quenching with aqueous sodium bicarbonate. Separate the mixture, and extract the aqueous phase with methylene chloride. Wash combined organic phases with aqueous sodium bicarbonate and brine, dry over anhydrous magnesium sulfate, filter, and concentrate to give a purple oil. Purify by flash chromatography using 25% ethyl acetate in hexanes to give 4.37 g (80%) of pure 4-chloro-2-isopropylphenol as a clear oil. 1H NMR (400 MHz, CDCl3) δ 7.15 (d, J=2.6 Hz, 1H), 7.01 (dd, J=8.5, 2.6 Hz, 1H), 6.66 (d, J=8.5 Hz, 1H), 4.77 (s, 1H), 3.17 (sept, 1H), 1.24 (d, J=6.9 Hz, 6H). 13C NMR (101 MHz, CDCl3) δ 151.26, 136.37, 126.56, 126.36, 125.81, 116.46, 27.14, 22.33. MS: m/e 171.

Provenance & Evidence