反应详情

2-(3-Ethoxycarbonylmethyl-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-6-yloxy)-thiazole-5-carboxylic acid tert-butyl ester (3.3 g, 7.6 mmol) was treated with TFA (40 mL) and stirred at room temperature for overnight. The reaction mixture was concentrated and purified by column chromatography (silica, DCM/MeOH=20:1) affording the title compound (2.5 g, 87%) as a white foam. 1H NMR (CDCl3) δ 7.98 (s, 1H), 7.45 (d, 1H), 7.19 (d, 1H), 5.67 (dd, 1H), 4.20 (q, 2H), 3.12 (dd, 1H), 2.43 (m, 1H), 2.39 (s, 3H), 1.56 (s, 9H), 1.24 (t, 3H). MS found: (M+H)+: 378.05.

1. concentrationThe reaction mixture was concentrated
2. custompurified by column chromatography (silica, DCM/MeOH=20:1)