Hydrochloric Acid → [6-(5-tert-Butoxycarbonylamino-thiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid

Participants

Reaction Steps

To a solution of [6-(5-tert-butoxycarbonylamino-thiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester (270 mg, 0.6 mmol) in THF (7 mL) was added LiOH (76 mg, 1.8 mmol) in water (3.5 mL). The mixture was stirred at room temperature for 3 h and acidified by 1N HCl to pH 3. The mixture was extracted by ethyl acetate. The organic layer was washed with water and brine, dried over Na2SO4 and concentrated. The residue was purified by HPLC affording the title compound (100 mg, 40%) as a white solid. 1H NMR (CD3OD) δ 7.29 (s, 1H), 7.19 (s, 1H), 6.75 (s, 1H), 5.69 (dd, 1H), 3.19 (m, 1H), 2.40 (s, 3H), 2.35 (m, 1H), 1.52 (s, 9H). MS found: (M+H)+=421.20.

Provenance & Evidence