Lithium Chloride → 1-[1-methyl-5-(4-methylphenyl)-1H-pyrazol-4-yl]ethanone

HRID 1907175Notes

Reaction equation

C([Sn](CCCC)(CCCC)[C:6]([O:8]CC)=[CH2:7])CCC.I[C:20]1[CH:21]=[N:22][N:23]([CH3:32])[C:24]=1[C:25]1[CH:30]=[CH:29][C:28]([CH3:31])=[CH:27][CH:26]=1.[Cl-].[Li+]>CN(C)C=O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH3:32][N:23]1[C:24]([C:25]2[CH:30]=[CH:29][C:28]([CH3:31])=[CH:27][CH:26]=2)=[C:20]([C:6](=[O:8])[CH3:7])[CH:21]=[N:22]1

Participants

Conditions

Temperature: 90 °C

Procedure

Tributyl(1-ethoxyvinyl)stannane (95%, 1.39 mL, 3.88 mmol) was added to a mixture of 4-iodo-1-methyl-5-(4-methylphenyl)-1H-pyrazole (768 mg, 2.58 mmol), tetrakis(triphenylphosphine)palladium(0) (298 mg, 0.258 mmol) and lithium chloride (98%, 279 mg, 6.45 mmol) in N,N-dimethylformamide (20 mL), and the reaction was stirred at 90° C. for 18 hours. After cooling, the mixture was filtered through Celite, and concentrated in vacuo; silica gel chromatography (Gradient: 10% to 50% ethyl acetate in heptane) afforded the product as a colorless oil. Yield: 460 mg, 2.15 mmol, 83%. LCMS m/z 215.3 (M+1). 1H NMR (400 MHz, CDCl3) δ 2.17 (s, 3H), 2.45 (br s, 3H), 3.69 (s, 3H), 7.28 (br AB quartet, JAB=8 Hz, ΔvAB=28 Hz, 4H), 7.99 (s, 1H).

Workup

temperatureAfter cooling
filtrationthe mixture was filtered through Celite
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-fb00c166b9eb47cfa91b27744b8d26bb
Source dataset: uspto-grants-2013_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08598155B2

Reaction notes

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