Trimethyl borate → (4-Fluoro-5-isopropyl-2-methoxyphenyl)boronic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-fluoro-4-iodo-2-isopropyl-5-methoxybenzene (Example 77, 2.61 g, 8.88 mmol) in THF at −78° C., n-BuLi (4.26 ml, 10.65 mmol, 2.5 M) was added dropwise. The solution was stirred at −78° C. for 30 min. Trimethyl borate (2.98 ml, 26.6 mmol) was added. The solution was then stirred at −78° C. for 3 h. The reaction was quenched at −78° C. with saturated ammonium chloride and the mixture was warmed to room temperature. The organic was extracted with ethyl acetate (3×50 ml). The combined ethyl acetate layers were washed with brine and dried over sodium sulfate. The title compound was obtained as a solid pure enough for next step. Further purification with silica gel caused decomposition of product. 1H NMR (CDCl3, 500 MHz) δ 7.74 (d, J=10.0 Hz, 1H), 6.62 (d, J=12.5 Hz, 1H), 5.65 (br s, 2H), 3.92 (s, 3H), 3.20 (m, 1H), 1.22 (m, 6H).

Provenance & Evidence