Diisopropylamine → 1-(Difluoromethyl)-4-((trimethylsilyl)ethynyl)-1H-pyrazole

HRID 2205944Notes

Reaction equation

HRID 2205944 reaction equation
I[C:2]1[CH:3]=[N:4][N:5]([CH:7]([F:9])[F:8])[CH:6]=1.[Si:10]([C:14]#[CH:15])([CH3:13])([CH3:12])[CH3:11].C(NC(C)C)(C)C.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>CN(C=O)C.[Cu]I.C1CCCCC1>[F:8][CH:7]([F:9])[N:5]1[CH:6]=[C:2]([C:15]#[C:14][Si:10]([CH3:13])([CH3:12])[CH3:11])[CH:3]=[N:4]1

Participants

8

Reactant 4

HCID 7912DiisopropylamineHCID 11776TriphenylphosphineHCID 66111TrimethylsilylacetyleneHCID 579309641-(Difluoromethyl)-4-iodo-1H-pyrazole

Product 1

HCID 682906451-(Difluoromethyl)-4-((trimethylsilyl)ethynyl)-1H-pyrazole

Reagents, catalysts & solvents 3

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 6228DimethylformamideSolventHCID 8078CyclohexaneSolvent

Conditions

Temperature
60 °C

Procedure

4-Iodo-1-difluoromethylpyrazole (521 mg, 1.81 mmole) was dissolved in DMF (3 mL). TMS-acetylene (0.43 ml) was added followed by di-isopropylamine (395 uL), copper(I) iodide (27 mg) and triphenylphosphine (112 mg). The reaction was flushed with nitrogen. Palladium acetate (32 mg) was added and the reaction flushed again with nitrogen (×3) and was heated at 60° C. for 65 minutes. The reaction was cooled and diluted with ethyl acetate (20 mL). The solution was washed with water (3×10 mL) and with brine then dried and concentrated in vacuo. The residue was purified using preparative TLC eluting with 1:1 dichloromethane:cyclohexane to afford the title compound (413 mg 1.92 mmole). 1H-NMR (CDCl3, 500 MHz): δ 0.25 (s, 9H), 7.15 (t, J=60.2 Hz, 1H), 7.71 (s, 1H), 7.94 (s, 1H).

Workup

  1. customThe reaction was flushed with nitrogen
  2. additionPalladium acetate (32 mg) was added
  3. customthe reaction flushed again with nitrogen (×3)
  4. temperatureThe reaction was cooled
  5. additiondiluted with ethyl acetate (20 mL)
  6. washThe solution was washed with water (3×10 mL) and with brine
  7. customthen dried
  8. concentrationconcentrated in vacuo
  9. customThe residue was purified
  10. washeluting with 1:1 dichloromethane

Sources & evidence

ORD record
ord-d4e136c9a8de498fbd595aec3783a86b
Source dataset
uspto-grants-2016_06
Patent number
US09371319B2

Reaction notes

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