Reaktion #331838

Reaktionsgleichung

Selectfluor

Selectfluor

Selectfluor

ethyl 1-(1-methylethyl)-1H-pyrazole-5-carboxylate

Selectfluor

acetonitrile

→

title compound

Ethyl 4-fluoro-1-(1-methylethyl)-1H-pyrazole-5-carboxylate

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

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

Vorschrift

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.

Quelle