反应详情

A mixture of [6-(5-bromo-[1,3,4]thiadiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester (0.53 g, 1.28 mmol) and Pd/C (0.5 g) in EtOH (15 mL) was hydrogenated at 45 psi for 1 hour. The mixture was filtered through a pad of celite and concentrated in vacuo. The residue was purified by silica gel flash column chromatography (DCM:MeOH 95:5) to give [1-hydroxy-4-methyl-6-([1,3,4]thiadiazol-2-yloxy)-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester (0.3 g, 70%). 1H NMR (400 MHz, DMSO): δ 9.15 (s, 1H), 7.40 (s, 1H), 7.28 (s, 1H), 5.52 (d, J=8.8 Hz, 1H), 4.00 (q, J=7.2 Hz, 2H), 3.10 (dd, J=4.0, 15.6 Hz, 1H), 2.52-2.45 (m, 1H), 2.30 (s, 3H), 1.10 (t, J=6.8 Hz, 3H). MS (ESI) m/z=335 [M+H]+.

1. filtrationThe mixture was filtered through a pad of celite
2. concentrationconcentrated in vacuo
3. customThe residue was purified by silica gel flash column chromatography (DCM:MeOH 95:5)