Hydrochloric Acid → HCID 58292572, compound

Participants

Reaction Steps

To a solution of (3R)-(1-hydroxy-6-methoxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-acetic acid ethyl ester (0.68 g, 2.57 mmol) in THF (7 mL) was added a solution of LiOH (0.31 g, 12.87 mmol) in water (7 mL) at 0° C. The resulting mixture was stirred at room temperature for 3 hours then acidified to pH 2 using 6M hydrochloric acid and extracted with EtOAc. The organic extracts were washed with water, brine, dried over Na2SO4, and concentrated in vacuo. The residue was purified by silica gel flash column chromatography (0-5% MeOH in DCM) to give (3R)-(1-hydroxy-6-methoxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-acetic acid as an off white solid (0.45 g, 74%). mp 48.2-50° C. 1HNMR (400 MHz, DMSO-d δ 9.10 (s, 1H), 7.02 (d, J=2.34 Hz, 1H), 6.83 (d, J=1.76 Hz, 1H), 5.42 (dd, J=9.67, 2.64 Hz, 1H), 3.73 (s, 3H), 3.01 (dd, J=15.38, 2.49 Hz, 1H), 2.24 (s, 3H), 2.03 (m, 1H). MS (ESI) m/z: 235 (M−1)−. HPLC purity: 98.31% (Maxplot), 97.78% (220 nm).

Provenance & Evidence