Potassium Carbonate → (2S)-3,3-dimethyl-1-[3-(trifluoromethyl)-1H-pyrazol-1-yl]-2-butanol

HRID 1182302Notes

Reaction equation

HRID 1182302 reaction equation
[C:1]([C@H:5]1[CH2:9]OS(=O)(=O)[O:6]1)([CH3:4])([CH3:3])[CH3:2].[F:12][C:13]([F:20])([F:19])[C:14]1[CH:18]=[CH:17][NH:16][N:15]=1.C(=O)([O-])[O-].[K+].[K+].C(Cl)(=O)C.CO.C(=O)(O)[O-].[Na+]>CN(C)C=O>[CH3:2][C:1]([CH3:4])([CH3:3])[C@H:5]([OH:6])[CH2:9][N:16]1[CH:17]=[CH:18][C:14]([C:13]([F:20])([F:19])[F:12])=[N:15]1

Participants

7

Reactant 5

HCID 11430Potassium CarbonateHCID 516892Sodium BicarbonateHCID 18070343-(Trifluoromethyl)pyrazoleHCID 22256297Acetyl chloride methanolHCID 58981698(4S)-4-tert-butyl-1,3,2-dioxathiolane 2,2-dioxide

Product 1

HCID 69513260(2S)-3,3-dimethyl-1-[3-(trifluoromethyl)-1H-pyrazol-1-yl]-2-butanolYield 56.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
100 °C

Procedure

To 999.9 mg (5.55 mmol) of (4S)-4-tert-butyl-1,3,2-dioxathiolane 2,2-dioxide in 18 mL of N,N-dimethylformamide was added 755.0 mg (5.55 mmol) of 3-(trifluoromethyl)-1H-pyrazole. Then, 805.2 mg (5.83 mmol) of potassium carbonate was added, and the mixture was heated at 100° C. for 22 h. The resulting solution was cooled and 20 mL of acetyl chloride:methanol (1:9) were added. The reaction mixture was stirred for 2 h, and then saturated aqueous sodium bicarbonate was added. The mixture was extracted with ethyl acetate, and the extract was dried over anhydrous magnesium sulfate, filtered, and concentrated. The residue was purified by silica gel column chromatography eluting with an ethyl acetate:hexanes solution (1:4) to give 736.5 mg (56%) of (2S)-3,3-dimethyl-1-[3-(trifluoromethyl)-1H-pyrazol-1-yl]-2-butanol and a small amount of the other regioisomer. Rf=0.23 (1:4 ethyl acetate:hexanes); 1H-NMR (300 MHz, DMSO-d6): δ 7.90 (s, 1H), 6.65 (d, J=2 Hz, 1H), 4.93 (br s, 1H), 4.30 (dd, J=14 Hz, J=2 Hz, 1H), 3.96 (dd, J=14 Hz, 10 Hz, 1H), 3.45 (d, J=10 Hz, 1H), 0.90 (s, 9H); ES-LCMS m/z 237 (M+H).

Workup

  1. temperatureThe resulting solution was cooled
  2. extractionThe mixture was extracted with ethyl acetate
  3. dry with materialthe extract was dried over anhydrous magnesium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customThe residue was purified by silica gel column chromatography
  7. washeluting with an ethyl acetate

Sources & evidence

ORD record
ord-ac66a574e65b4126bb07754291f2a97d
Source dataset
uspto-grants-2007_10
Patent number
US07288541B2

Reaction notes

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