Perfluoro-1-butanesulfonyl fluoride → 1-Methyl-3-bromo-5-(nonafluorobutanesulfonyloxy)pyrazole

HRID 1180629Notes

Reaction equation

HRID 1180629 reaction equation
C[Si]([N-][Si](C)(C)C)(C)C.[Na+].[CH3:11][N:12]1[C:16](=[O:17])[CH:15]=[C:14]([Br:18])[NH:13]1.[F:19][C:20]([F:35])([C:31]([F:34])([F:33])[F:32])[C:21]([F:30])([F:29])[C:22]([F:28])([F:27])[S:23](F)(=[O:25])=[O:24]>O1CCCC1.O>[CH3:11][N:12]1[C:16]([O:17][S:23]([C:22]([F:27])([F:28])[C:21]([F:29])([F:30])[C:20]([F:19])([F:35])[C:31]([F:34])([F:33])[F:32])(=[O:25])=[O:24])=[CH:15][C:14]([Br:18])=[N:13]1

Participants

6

Reactant 3

HCID 67814Perfluoro-1-butanesulfonyl fluorideHCID 2724254Sodium bis(trimethylsilyl)amideHCID 221479883-bromo-1-methyl-1H-pyrazol-5-ol

Product 1

HCID 117755091-Methyl-3-bromo-5-(nonafluorobutanesulfonyloxy)pyrazoleYield 79%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of sodium bis(trimethylsilyl)amide in tetrahydrofuran (1M, 0.70 mL, 0.70 mmol) was added at −78° C. under nitrogen to a stirred solution of 1-methyl-3-bromo-5-pyrazolone from Step 1 (0.10 g, mmol) in dry tetrahydrofuran (2 mL). After 10 min, nonafluorobutanesulfonyl fluoride (0.13 mL, 0.70 mmol) was added dropwise. The resulting gel was warmed to room temperature and stirred for 1 hour. The solution was diluted with water (10 mL) and extracted with ethyl acetate (2×10 mL). The extracts were dried (Na2SO4) and concentrated. Flash column chromatography on silica, eluting with 10% ethyl acetate—isohexane, gave 1-methyl-3-bromo-5-(nonafluorobutanesulfonyloxy)pyrazole (0.204 g, 79%) as a colourless oil. δ (1H, 500 MHz, CDCl3) 3.80 (3H, s), 6.19 (1H, s). Step 3: 1-methyl-3-bromo-5-(5-methylpyridin-2-yl)pyrazole

Workup

  1. extractionextracted with ethyl acetate (2×10 mL)
  2. dry with materialThe extracts were dried (Na2SO4)
  3. concentrationconcentrated
  4. washFlash column chromatography on silica, eluting with 10% ethyl acetate—isohexane

Sources & evidence

ORD record
ord-c858c21178084b8eb2ff634a5eb5d478
Source dataset
uspto-grants-2007_10
Patent number
US07282513B2

Reaction notes

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