反应详情

To a round-bottom flask containing 2-(5,7-difluoro-quinolin-6-yl)-malonic acid diethyl ester (2.48 g, 7.68 mmol) were added ethanol (77 mL) and 10% aqueous NaOH (103.2 mL). The solution was refluxed for 3 h. After such time the ethanol was removed under reduced pressure to form a yellow suspension and tetrahydrofuran (50 mL) was added to give a clear yellow solution which was placed in an ice bath and stirred. 6N Hydrochloric acid (50 ml) was slowly added to the solution to reach pH 1. The light orange solution was refluxed for another hour, at which time two layers formed. The top tetrahydrofuran layer was collected and the aqueous solution was extracted with dichloromethane. The organic layers were brined and dried with anhydrous sodium sulfate. The solution was then filtered and the filtrate was concentrated to obtain the title compound (1.20 g, 70.1%). 1H NMR (300 MHz, DMSO-d6) δ 12.82 (s, 1H), 8.98˜9.00 (m, 1H), 8.47˜8.50 (d, 1H), 7.61˜7.74 (m, 2H), 3.86 (s, 2H). ES-MS m/z: 224.2 (M++1).

1. temperatureThe solution was refluxed for 3 h
2. customAfter such time the ethanol was removed under reduced pressure
3. customto form a yellow suspension and tetrahydrofuran (50 mL)
4. additionwas added
5. customto give a clear yellow solution which
6. customwas placed in an ice bath
7. temperatureThe light orange solution was refluxed for another hour, at which time two layers
8. customformed
9. customThe top tetrahydrofuran layer was collected
10. extractionthe aqueous solution was extracted with dichloromethane
11. dry with materialdried with anhydrous sodium sulfate
12. filtrationThe solution was then filtered
13. concentrationthe filtrate was concentrated