N-bromobutanimide → tert-Butyl 3-(bromomethyl)-1H-pyrazole-1-carboxylate

HRID 1867137Notes

Reaction equation

HRID 1867137 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH:12]=[CH:11][C:10]([CH3:13])=[N:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Br:14]N1C(=O)CCC1=O>C(Cl)(Cl)(Cl)Cl.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>[C:1]([O:5][C:6]([N:8]1[CH:12]=[CH:11][C:10]([CH2:13][Br:14])=[N:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 21035385tert-Butyl 3-methyl-1H-pyrazole-1-carboxylate

Product 1

HCID 23573257tert-Butyl 3-(bromomethyl)-1H-pyrazole-1-carboxylateYield 307.7%

Reagents, catalysts & solvents 2

HCID 7187Benzoyl PeroxideCatalystHCID 5943Carbon TetrachlorideSolvent

Procedure

3-Methylpyrazole-1-carboxylic acid tert-butyl ester (6.0 g, 33 mmol), N-bromosuccinimide (1.0 g, 5.6 mmol) and benzoyl peroxide (50 mg) were dissolved in 20 mL of carbon tetrachloride. The reaction was heated at reflux for 16 h. The reaction was cooled to room temperature, filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica, 1:4 EtOAc/hexanes) gave a light yellow oil (4.5 g, 53%): 1H NMR (300 MHz, CDCl3) δ 8.03 (d, J=2.6 Hz, 1H), 6.47 (d, J=2.6 Hz, 1H), 4.48 (s, 2H), 1.64 (s, 9H).

Workup

  1. temperatureThe reaction was heated
  2. temperatureat reflux for 16 h
  3. filtrationfiltered
  4. concentrationconcentrated under reduced pressure
  5. customPurification by flash column chromatography (silica, 1:4 EtOAc/hexanes)

Sources & evidence

ORD record
ord-c2465a665b964268a1ad751209e81e2d
Source dataset
uspto-grants-2009_12
Patent number
US07629363B2

Reaction notes

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