Hydrochloric Acid → Ethyl 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylate

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Reaction Conditions

Reaction Steps

A solution of diethylmalonate (80 g, 0.50 mol) was added slowly to a suspension of sodium hydride (60% in mineral oil, 22 g, 0.55 mol) in dimethylacetamide under N2 atmosphere. The mixture was allowed to stir at room temperature until the evolution of hydrogen gas ceased, then heated to 90° C. for 30 min. and cooled to room temperature. A solution of isatoic anhydride (89.72 g, 0.55 mmol) in dimethylacetamide was added slowly and heated at 120° C. for 15 h. The mixture was cooled to room temperature, poured into ice water and acidified by cold 10% HCl. The solids formed were filtered and washed several times by water to yield 55 g (47%) of white solids. Mp 173° C. 1H NMR (DMSO-d6): δ 1.30 (t, J=6.9 Hz, 3H), 4.33 (q, J=6.9 Hz, 2H), 7.18 (t, J=7.5 Hz, 1H), 7.26 (d, J=8.2 Hz, 1H), 7.62 (t, J=7.2 Hz, 1H), 7.93 (d, J=8.0 Hz, 1H) 11.50 (s, 1H), 13.5 (s, 1H). EIMS m/z 234 (M+1), 256 (M+23). Anal. (C12H11NO4) C, H, N.

Provenance & Evidence