Phosphorus oxychloride → HCID 89375780, compound

Participants

Reaction Steps

3,4-Dihydro-2H-pyrano[2,3-d]pyridazin-5(6H)-one (400 mg, 2.63 mmol) was stirred in phosphorus oxychloride (4 mL, 6.58 g, 42.9 mmol) at 95° C. for nearly 2 hours. The reaction was then cooled to room temperature and excess phosphorus oxychloride was removed in vacuo. The residue was treated with ice (˜15 g) and very slowly with solid potassium carbonate until pH >7. A tan solid was isolated by filtration and dried under vacuum to afford the title compound (267 mg, 57% yield). MS (ESI) [m/e, (M)+]=170.6. 1H NMR (400 MHz, chloroform-d) δ ppm 8.68 (s, 1H), 4.28-4.42 (m, 2H), 2.78 (t, J=6.32 Hz, 2H), 2.05-2.20 (m, 2H).

Provenance & Evidence