Reaktion #792175

Reaktionsgleichung

potassium carbonate

Water

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

2,2,2-trifluoroethyl trifluoromethanesulfonate

→

title product

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

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe stirred suspension was then cooled to 5° C.
2. 2
   TemperaturThe reaction mixture was warmed to room temperature
3. 3
   Temperaturheated
4. 4
   Temperaturto reflux, at which time thin layer chromatography
5. 5
   Sonstigethe reaction
6. 6
   Extraktionwas then extracted with ethyl ether
7. 7
   ExtraktionThe ether extract
8. 8
   Trocknenwas dried over magnesium sulfate
9. 9
   Einengenconcentrated

Vorschrift

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) (0.8 g, 3 mmol) stirred in 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-trifluoroethyl 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.

Quelle