Acetonitrile → ethyl 4-fluoro-1-(1-methylethyl)-1H-pyrazole-5-carboxylate

Temperature

100 °C

A microwave vial was charged with ethyl 1-(1-methylethyl)-1H-pyrazole-5-carboxylate (0.15 g) and Selectfluor™ (0.38 g) followed by acetonitrile (3 ml) and acetic acid (1 ml). The mixture was heated at 100° C. under microwave irradiation for 180 min. Selectfluor™ (0.076 g) was added and the mixture heated at 100° C. under microwave irradiation for 60 min. Further Selectfluor™ (0.15 g) was added and the mixture heated at 100° C. under microwave irradiation for 60 min. Further Selectfluor (0.38 g) was added and the mixture heated at 100° C. under microwave irradiation for 60 min. The solvent was removed in vacuo and the residue was partitioned between DCM (15 ml) and water (15 ml) and separated using a hydrophobic frit. The aqueous layer was extracted with dichloromethane (2×5 ml) and the combined organic layers were concentrated in vacuo. Purification by chromatography on silica gel (20 g silica cartridge), eluting with a gradient of 0-50% DCM in cyclohexane over 20 minutes gave the title compound (100 mg) as a colourless oil.

1. temperaturethe mixture heated at 100° C. under microwave irradiation for 60 min
2. temperaturethe mixture heated at 100° C. under microwave irradiation for 60 min
3. temperaturethe mixture heated at 100° C. under microwave irradiation for 60 min
4. customThe solvent was removed in vacuo
5. customthe residue was partitioned between DCM (15 ml) and water (15 ml)
6. customseparated
7. extractionThe aqueous layer was extracted with dichloromethane (2×5 ml)
8. concentrationthe combined organic layers were concentrated in vacuo
9. customPurification by chromatography on silica gel (20 g silica cartridge)
10. washeluting with a gradient of 0-50% DCM in cyclohexane over 20 minutes

ORD record

ord-44af04039a3743b0802e6c9f74901296

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08658635B2