反応 #10369

反応方程式

NaHCO3

ethanol

2,4,5-trifluoro-3-methoxybenzoic acid

oxalyl chloride

→

title compound

収率 98.8%

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

収率 98.8%

溶媒

dichloromethane

反応条件

後処理

1. 1
   workup.WAITat room temperature for 2.5 hours
2. 2
   濃縮The mixture is concentrated
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 dichloromethane
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 2,4,5-trifluoro-3-methoxybenzoic acid (2.513 g, 12.19 mmol) in dichloromethane (50 mL) at 0° C. is treated with oxalyl chloride (5.4 mL, 61.9 mmol) followed by N,N-dimethylformamide (4 drops). The mixture is stirred at 0° C. for 5 minutes and then at room temperature for 2.5 hours. The mixture is concentrated to near dryness and then co-evaporated from benzene. The resulting acid chloride is diluted with dichloromethane (50 mL), cooled to 0° C., and then anhydrous ethanol (7.30 mL, 124 mmol) is added dropwise. The resulting solution is stirred at room temperature for 4.5 hours, poured into saturated NaHCO3 solution, and extracted with dichloromethane. The combined organic extracts are washed with brine, dried over Na2SO4, filtered, and concentrated under vacuum to afford the title compound as a light yellow liquid (2.82 g). 1H NMR (CDCl3): δ 7.47 (ddd, 1H), 4.39 (q, 2H), 4.05 (s, 3H), 1.40 (t, 3H).

出典