反应详情

温度

60 °C

To a solution of (1,6-dihydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-acetic acid ethyl ester (0.44 g, 1.75 mmol) in acetonitrile (30 mL) was added 5-bromo-[1,3,4]thiadiazole-2-carbonitrile (0.6 g, 3.16 mmol) and potassium carbonate (0.73 g, 5.25 mmol). The suspension was heated at 60° C. for 6 hours. The mixture was cooled to 0° C., diluted with water and extracted with EtOAc (2×50 mL). The organic extracts were combined, dried over MgSO4 and concentrated in vacuo. The residue was purified by silica gel flash column chromatography (30-60% EtOAc/hexane) to give [6-(5-cyano-[1,3,4]thiadiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester (0.44 g, 72%). 1H NMR (400 MHz, DMSO-d6) δ ppm 9.41 (s, 1H), 7.55 (d, J=2.21 Hz, 1H), 7.43 (d, J=1.62 Hz, 1H), 5.59 (dd, J=8.72, 2.73 Hz, 1H), 4.04 (q, J=6.92 Hz, 2H), 3.16 (dd, J=15.56, 2.94 Hz, 1H), 2.37-2.43 (m, 1H), 2.35 (s, 3H), 1.14 (t, J=7.17 Hz, 3H).

1. temperatureThe mixture was cooled to 0° C.
2. extractionextracted with EtOAc (2×50 mL)
3. dry with materialdried over MgSO4
4. concentrationconcentrated in vacuo
5. customThe residue was purified by silica gel flash column chromatography (30-60% EtOAc/hexane)