반응 #10365

반응 방정식

ethanol

NaHCO3

oxalyl chloride

2,3,4,6-Tetrafluorobenzoic acid

→

title compound

수율 60.1%

2,3,4,6-Tetrafluorobenzoic acid ethyl ester

수율 60.1%

용매

dichloromethane

benzene

dichloromethane

반응 조건

후처리

1. 1
   기타to yield an oil that
2. 2
   온도cooled to 0° C. under an inert atmosphere
3. 3
   workup.WAITAfter 5 hours at room temperature
4. 4
   추출extracted with chloroform
5. 5
   세척The organic phase is washed with brine
6. 6
   건조dried over Na2SO4
7. 7
   여과filtered
8. 8
   농축concentrated under vacuum

실험 절차

2,3,4,6-Tetrafluorobenzoic acid (4.8 g, 24.7 mmol) in dichloromethane (80 mL) is cooled to 0° C. under a nitrogen atmosphere and treated with oxalyl chloride (11.2 mL, 128 mmol) followed by anhydrous N,N-dimethylformamide (2 drops). The mixture is warmed to room temperature and stirred for 2 hours. The solution is co-evaporated with benzene to yield an oil that is taken up in dichloromethane (80 mL), cooled to 0° C. under an inert atmosphere, and treated with anhydrous ethanol (15 mL, 258 mmol). After 5 hours at room temperature, the solution is poured into saturated NaHCO3 and extracted with chloroform. The organic phase is washed with brine, dried over Na2SO4, filtered, and concentrated under vacuum to provide the title compound (3.3 g). This material is used without further purification. 1H NMR (CDCl3): δ 6.93–6.75 (m, 1H), 4.42 (q, 2H), 1.39 (t, 3H).

출처