Reacción #2453338

Ecuación de reacción

acetonitrile

2,2,2-trifluoro-ethyl trifluoromethanesulfonate

ethyl 1-(3-chloro-2-pyridinyl)-2,3-dihydro-3-oxo-1H-pyrazole-5-carboxylate

Ethyl 1-(3-chloro-2-pyridinyl)-2,3-dihydro-3-oxo-1H-pyrazole-5-carboxylate

product

Ethyl 1-(3-chloro-2-pyridinyl)-2,3-dihydro-3-oxo-1H-pyrazole-5-carboxylate

potassium carbonate

→

title product

Ethyl 1-(3-chloro-2-pyridinyl)-3-(2,2,2-trifluoroethoxy)-1H-pyrazole-5-carboxylate

Disolventes

Water

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroat −5° C.
2. 2
   workup.STIRRINGThe suspension was stirred for 15 minutes at 20° C
3. 3
   TemperaturaThe reaction mixture was warmed to room temperature
4. 4
   Temperaturaheated
5. 5
   Temperaturato reflux, at which time thin layer chromatography
6. 6
   Otrothe reaction
7. 7
   Extracciónwas then extracted with ethyl ether
8. 8
   ExtracciónThe ether extract
9. 9
   Secadowas dried over magnesium sulfate
10. 10
    Concentraciónconcentrated

Procedimiento

To a suspension of ethyl 1-(3-chloro-2-pyridinyl)-2,3-dihydro-3-oxo-1H-pyrazole-5-carboxylate (i.e. product of Step A) (0.1 g, 3 mmol) stirred is dry acetonitrile (15 mL) at −5° C. was added potassium carbonate (0.85 g, 6.15 mmol). The suspension was stirred for 15 minutes at 20° C. The stirred suspension was then cooled to 5° C. and 2,2,2-trifluoro-ethyl trifluoromethanesulfonate (0.8 g, 3.45 mmol) was added dropwise. The reaction mixture was warmed to room temperature and then heated to reflux, at which time thin layer chromatography showed the reaction to be complete. Water (25 mL) was added to the reaction mixture, which was then extracted with ethyl ether. The ether extract was dried over magnesium sulfate and concentrated to yield the title product compound (1.05 g) as a pale yellow oil.

Fuente