4-Ethoxy-1,1,1-trifluoro-3-buten-2-one → 3-(Trifluoromethyl)pyrazole

To a stirred solution of hydrazine monochloride (6.62 g, 1.6 eq.) in EtOH (300 mL) was added dropwise compound 231 (10.16 g, 1 eq.) in EtOH (200 mL). The reaction mixture was refluxed for 6 hrs and evaporated to dryness. Water and EtOAc were added to the residue. The organic layer was washed with water and brine, dried over Na2SO4, filtered, and concentrated under reduced pressure to yield compound 233a as a brown solid in 86% yield. 1H NMR (CDCl3, 376 MHz) δ (ppm) 6.66 (d, J=2.30 Hz, 1H), 7.72 (d, J=2.30 Hz, 1H); 19F NMR (CDCl3, MHz) δ (ppm) 61.41 (s, 3F).

1. temperatureThe reaction mixture was refluxed for 6 hrs
2. customevaporated to dryness
3. additionWater and EtOAc were added to the residue
4. washThe organic layer was washed with water and brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure

ORD record

ord-dd4b4e4226f741ccae6d6098331faee9

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08377962B2