Phosphorus oxychloride → HCID 67083777, compound

Participants

Reaction Steps

To a 50 mL round bottom flask charged with a magnetic stir bar and ethyl 6,7-dimethoxy-4-oxo-1,4-dihydrocinnoline-3-carboxylate (1.00 g, 3.6 mmol) (Method 5) was added phosphorous oxychloride (15 mL). The reaction flask was fitted with a reflux condenser and heated to reflux for 2 h before being allowed to cool to rt. The crude reaction mixture was concentrated in vacuo, and the residue was treated with aqueous NaHCO3 (˜25 mL). The crude product precipitated from solution and was collected via vacuum filtration using a Buchner funnel. The solid was washed water (1×100 mL) and diethyl ether (1×100 mL) to yield 0.941 g (88%) of the title compound as a light brown solid that was used without further purification. 1H NMR: 7.98 (s, 1H), 7.50 (s, 1H), 4.55 (q, 2H), 4.13 (s, 6H), 1.45 (t, 3H); m/z 298.

Provenance & Evidence