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

Temperature

5 °C

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.

1. customat −5° C.
2. stirringThe suspension was stirred for 15 minutes at 20° C
3. temperatureThe reaction mixture was warmed to room temperature
4. temperatureheated
5. temperatureto reflux, at which time thin layer chromatography
6. customthe reaction
7. extractionwas then extracted with ethyl ether
8. extractionThe ether extract
9. dry with materialwas dried over magnesium sulfate
10. concentrationconcentrated

ORD record

ord-f3cda6405f384a8e8fa54770cd842a0d

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08697734B2