Sodium Chloride → Methyl 4-chloro-2-oxo-1,2-dihydroquinoline-3-carboxylate

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Reaction Steps

Dimethylmalonate (2.2 mL, 19.2 mmol) was added slowly to a suspension of 60% sodium hydride in mineral oil (0.81 g, 20.3 mmol) in anhydrous DMF (100 mL) at −10° C. under nitrogen. After stirring at room temperature for 30 minutes, isatoic anhydride (3.0 g, 18.4 mmol) was added, and the reaction mixture was heated at 115° C. for 2.5 hours. The reaction was then cooled to −40° C. and oxalyl chloride (6 mL, 68.8 mmol) was slowly added. The reaction was stirred at room temperature for 20 minutes, and was then poured into 1200 mL of 10% NaCl at 0° C. The resultant precipitate was collected by filtration to give crude methyl 4-chloro-2-oxo-1,2-dihydroquinoline-3-carboxylate (1.40 g, 32%), which was used without further purification. 1H NMR (400 MHz, DMSO-d6) δ3.87 (s, 3H), 7.39 (m, 2H), 7.70 (m, 1H), 7.92 (d, J=8.4 Hz, 1H), 12.49 (s, 1H). MS 238 (MH+).

Provenance & Evidence