Hydrochloric Acid → HCID 58292574, 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 (0.2 g, 0.8 mmol) and 3,6-dichloro-pyridazine (0.24 g, 1.6 mmol) in DMF (15 mL) at 0° C. was added NaH (0.1 g, 2.4 mmol) 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 dilute HCl. The mixture was extracted with EtOAc (2×10 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-chloro-pyridazin-3-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester (0.12 g, 42%). 1H NMR (400 MHz, CDCl3): δ 7.49 (d, J=8.8 Hz, 1H), 7.33 (d, J=2.0 Hz, 1H), 7.16 (d, J=9.6 Hz, 1H), 7.11 (s, 1H), 5.66 (dd, J=2.4, 9.6 Hz, 1H), 4.20 (q, J=7.2 Hz, 2H), 3.10 (dd, J=2.0, 15.6 Hz, 1H), 2.44-2.38 (m, 1H), 2.35 (s, 3H), 1.26 (t, J=7.2 Hz, 3H). MS (ESI) m/z=363 [M+H]+.

Provenance & Evidence