反応 #10364

反応方程式

NaHCO3

ethanol

2,3,4,5-tetrafluorobenzoic acid

oxalyl chloride

→

title compound

収率 100.3%

2,3,4,5-Tetrafluorobenzoic acid ethyl ester

収率 100.3%

溶媒

dichloromethane

反応条件

後処理

1. 1
   workup.WAITat room temperature for 1.5 hours
2. 2
   濃縮The mixture is concentrated to dryness
3. 3
   workup.ADDITIONThe resulting acid chloride is diluted with dichloromethane (50 mL)
4. 4
   温度cooled to 0° C.
5. 5
   workup.STIRRINGThe resulting solution is stirred at room temperature for 4.5 hours
6. 6
   抽出extracted with chloroform
7. 7
   洗浄The combined organic extracts are washed with brine
8. 8
   乾燥dried over Na2SO4
9. 9
   ろ過filtered
10. 10
    濃縮concentrated under vacuum

実験手順

A solution of 2,3,4,5-tetrafluorobenzoic acid (4.68 g, 24.1 mmol) in dichloromethane (50 mL) at 0° C. is treated with oxalyl chloride (11.5 mL, 132 mmol) followed by N,N-dimethylformamide (4 drops). The mixture is stirred at 0° C. for 5 minutes and then at room temperature for 1.5 hours. The mixture is concentrated to dryness and subsequently co-evaporated from benzene. The resulting acid chloride is diluted with dichloromethane (50 mL), cooled to 0° C., and anhydrous ethanol (15.0 mL, 256 mmol) is added dropwise. The resulting solution is stirred at room temperature for 4.5 hours, then poured into saturated NaHCO3 and extracted with chloroform. The combined organic extracts are washed with brine, dried over Na2SO4, filtered, and concentrated under vacuum to afford the title compound (5.37 g). 1H NMR (CDCl3): δ 7.67–7.55 (m, 1H), 4.42 (q, 2H), 1.41 (t, 3H).

出典