Hydrochloric Acid → HCID 67252242, compound

Participants

Reaction Steps

To a stirred solution of (1,6-dihydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-acetic acid ethyl ester (1.0 g, 3.9 mmol) and 6-chloro-pyridazine-3-carbonitrile (1.12 g, 7.9 mmol) in THF (50 mL) at 0° C. was added NaH (0.38 g) in portions. The reaction mixture was allowed to warm to room temperature and stirred for 12 hours. Saturated NH4Cl (10 mL) was added at 0° C. and the solution acidified to pH˜4 with 1N HCl. The mixture was extracted with EtOAc (2×15 mL) and the organic extracts washed with water (10 mL), dried and concentrated in vacuo. The residue was purified by silica gel flash column chromatography (DCM:MeOH 95:5) to give [6-(6-cyano-pyridazin-3-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester (0.75 g, 53%). 1H NMR (400 MHz, CDCl3): δ 9.27 (s, 1H), 8.36 (d, J=9.2 Hz, 1H), 7.71 (d, J=9.2 Hz, 1H), 7.33 (d, J=2.0 Hz, 1H), 7.18 (d, J=1.6 Hz, 1H), 5.55 (dd, J=2.4, 9.2 Hz, 1H), 4.04 (q, J=6.8 Hz, 2H), 3.14 (dd, J=2.4, 15.6 Hz, 1H), 2.36-2.32 (m, 1H), 2.31 (s, 3H), 1.13 (t, J=6.8 Hz, 3H). MS (ESI) m/z=354 [M+H]+.

Provenance & Evidence