Hydrochloric Acid → 1-(5-Methyl-1-(2,2,2-trifluoroethyl)-1H-pyrazol-4-yl)ethanone

HRID 2425544Notes

Reaction equation

HRID 2425544 reaction equation
C(O[CH:4]=[C:5]([C:9](=O)[CH3:10])[C:6](=[O:8])[CH3:7])C.[F:12][C:13]([F:18])([F:17])[CH2:14][NH:15][NH2:16].Cl>CO>[CH3:10][C:9]1[N:15]([CH2:14][C:13]([F:18])([F:17])[F:12])[N:16]=[CH:4][C:5]=1[C:6](=[O:8])[CH3:7]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 787402,2,2-TrifluoroethylhydrazineHCID 2404183-(Ethoxymethylene)pentane-2,4-dione

Product 1

HCID 671822581-(5-Methyl-1-(2,2,2-trifluoroethyl)-1H-pyrazol-4-yl)ethanoneYield 51%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

To a solution of 3-(ethoxymethylene)pentane-2,4-dione (Perkin 1. 2000, 1455-1460, 1.95 g, 12.5 mmol) in MeOH (33 ml) was added a solution of 2,2,2-trifluoroethylhydrazine (1.54 g, 13.5 mmol) and conc.HCl (2.6 ml) in MeOH (10 ml) (pre-cooled at 0° C.) dropwise at −15° C. The resulting mixture was then stirred for 24 h at rt. After removal of the solvent at rt, the residue was basified with 2N NaOH aq, and the aqueous layer was extracted several times with EtOAc. The combined organic extracts were dried over Na2SO4, and concentrated in vacuo to give the crude product as a single regioisomer (1.41 g, 51% yield). 1H NMR (300 MHz, CDCl3) δ 2.46 (3H, s), 2.62 (3H, s), 4.66 (1H, d, J=6.0 Hz), 4.72 (1H, d, J=9.0 Hz), 7.92 (1H, s). MS (ESI) m/z 207 (M+H)+

Workup

  1. customdropwise at −15° C
  2. customAfter removal of the solvent at rt
  3. extractionthe aqueous layer was extracted several times with EtOAc
  4. dry with materialThe combined organic extracts were dried over Na2SO4
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-785f54ba52934704bac387b914d79a63
Source dataset
uspto-grants-2011_06
Patent number
US07964732B2

Reaction notes

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