Реакция #10364

Уравнение реакции

NaHCO3

ethanol

2,3,4,5-tetrafluorobenzoic acid

oxalyl chloride

→

title compound

Выход 100.3%

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

Выход 100.3%

Растворители

dichloromethane

Условия реакции

Обработка

1. 1
   workup.WAITat room temperature for 1.5 hours
2. 2
   КонцентрированиеThe mixture is concentrated to dryness
3. 3
   workup.ADDITIONThe resulting acid chloride is diluted with dichloromethane (50 mL)
4. 4
   Температураcooled to 0° C.
5. 5
   workup.STIRRINGThe resulting solution is stirred at room temperature for 4.5 hours
6. 6
   Экстракцияextracted with chloroform
7. 7
   ПромывкаThe combined organic extracts are washed with brine
8. 8
   Сушкаdried over Na2SO4
9. 9
   Фильтрацияfiltered
10. 10
    Концентрированиеconcentrated under vacuum

Методика

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).

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