Реакция #10372

Уравнение реакции

NaHCO3

ethanol

3-methyl-2,4,5-trifluorobenzoic acid

oxalyl chloride

→

title compound

Выход 77.1%

2,4,5-Trifluoro-3-methylbenzoic acid ethyl ester

Выход 77.1%

Растворители

dichloromethane

Условия реакции

Обработка

1. 1
   Концентрированиеconcentrated
2. 2
   Другоеdried in vacuo
3. 3
   workup.ADDITIONThe acid chloride is diluted with dichloromethane
4. 4
   Температураcooled to 0° C.
5. 5
   workup.STIRRINGThe resulting solution is stirred at room temperature for 20 hours
6. 6
   Экстракцияextracted with dichloromethane
7. 7
   ПромывкаThe organic extracts are washed with brine
8. 8
   Сушкаdried over Na2SO4
9. 9
   Фильтрацияfiltered
10. 10
    Концентрированиеconcentrated under vacuum

Методика

A solution of 3-methyl-2,4,5-trifluorobenzoic acid (Shimizu T., Asai T., Kumai S., Jpn. Kokai Tokkyo Koho (1997) Japanese Appl. JP 95-219069, 4.3 g, 22.6 mmol) in dichloromethane (100 mL) at 0° C. is treated with oxalyl chloride (4.2 g, 33 mmol) followed by N,N-dimethylformamide (2 drops). The mixture is stirred at room temperature for 3 hours, concentrated and dried in vacuo. The acid chloride is diluted with dichloromethane, cooled to 0° C., and treated with absolute ethanol (10 mL, 170 mmol). The resulting solution is stirred at room temperature for 20 hours, poured into saturated NaHCO3 solution and extracted with dichloromethane. The organic extracts are washed with brine, dried over Na2SO4, filtered, and concentrated under vacuum to afford the title compound (3.8 g). 1H NMR (200 MHz, CDCl3): δ 7.67–7.26 (m, 1H), 4.44 (q, 2H), 2.27 (dd, 3H), 1.42 (t, 3H).

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