Hydrochloric Acid → (R)-(4-(1-(Benzyloxy)-3-fluoropropan-2-yl)-3-methylphenyl)boronic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 24B (0.46 g, 1.364 mmol) in THF (7 mL) at −78° C., was added a solution of n-BuLi (2.2 mL, 3.52 mmol) dropwise. The mixture was stirred at −78° C. for 15 min, then was treated with trimethyl borate (0.456 mL, 4.09 mmol). The reaction was stirred at −78° C. for 15 min, then was allowed to warm to rt and stir for 3 h. The reaction mixture was diluted with EtOAc (30 mL), treated with 1N HCl (20 mL). The mixture was stirred at rt for 1 h. The phases were separated, then the aqueous layer was extracted with EtOAc. The combined organic phase was washed with H2O and brine, dried (Na2SO4) and concentrated. The crude product was purified by flash chromatography (0 to 80% EtOAc/hexanes) to give 24C (0.2 g, 0.662 mmol, 48.5% yield). 1H NMR (400 MHz, chloroform-d) δ ppm 7.97-8.10 (m, 2H) 7.28-7.44 (m, 6H) 4.82 (d, J=5.56 Hz, 1H) 4.71 (d, J=5.56 Hz, 1H) 4.53-4.59 (m, 2H) 3.56-3.90 (m, 3H) 2.47 (s, 3H); 19F NMR (376 MHz, chloroform-d) δ ppm −223.99 (s, 1F).

Provenance & Evidence