反応 #10365

反応方程式

ethanol

NaHCO3

oxalyl chloride

2,3,4,6-Tetrafluorobenzoic acid

→

title compound

収率 60.1%

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

収率 60.1%

溶媒

dichloromethane

benzene

dichloromethane

反応条件

後処理

1. 1
   その他to yield an oil that
2. 2
   温度cooled to 0° C. under an inert atmosphere
3. 3
   workup.WAITAfter 5 hours at room temperature
4. 4
   抽出extracted with chloroform
5. 5
   洗浄The organic phase is washed with brine
6. 6
   乾燥dried over Na2SO4
7. 7
   ろ過filtered
8. 8
   濃縮concentrated under vacuum

実験手順

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).

出典