Reacción #10369

Ecuación de reacción

NaHCO3

ethanol

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

oxalyl chloride

→

title compound

Rendimiento 98.8%

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

Rendimiento 98.8%

Disolventes

dichloromethane

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITat room temperature for 2.5 hours
2. 2
   ConcentraciónThe mixture is concentrated
3. 3
   workup.ADDITIONThe resulting acid chloride is diluted with dichloromethane (50 mL)
4. 4
   Temperaturacooled to 0° C.
5. 5
   workup.STIRRINGThe resulting solution is stirred at room temperature for 4.5 hours
6. 6
   Extracciónextracted with dichloromethane
7. 7
   LavadoThe combined organic extracts are washed with brine
8. 8
   Secadodried over Na2SO4
9. 9
   Filtraciónfiltered
10. 10
    Concentraciónconcentrated under vacuum

Procedimiento

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).

Fuente