Benzoyl Peroxide → tert-butyl 4-(bromomethyl)-1H-pyrazole-1-carboxylate

HRID 1831950Notes

Reaction equation

HRID 1831950 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH:12]=[C:11]([CH3:13])[CH:10]=[N:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Br:14]N1C(=O)CCC1=O.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>C(Cl)(Cl)(Cl)Cl>[C:1]([O:5][C:6]([N:8]1[CH:12]=[C:11]([CH2:13][Br:14])[CH:10]=[N:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 7187Benzoyl PeroxideHCID 67184N-bromobutanimideHCID 23021524HCID 23021524, compound

Product 1

HCID 58066672tert-butyl 4-(bromomethyl)-1H-pyrazole-1-carboxylateYield 30%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

To a solution of 4-methylpyrazole-1-carboxylic acid tert-butyl ester (1.0 g, 5.5 mmol) in carbon tetrachloride (20 mL) was added N-bromosuccinimide (1.0 g, 5.6 mmol) and benzoyl peroxide (50 mg), and the reaction mixture was heated at reflux for 16 h. The reaction mixture was cooled to room temperature, filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica, 1:4 EtOAc/hexanes) provided 4-bromomethylpyrazole-1-carboxylic acid tert-butyl ester as a light yellow oil (0.42 g, 30%): 1H NMR (300 MHz, CDCl3) δ 8.10 (s, 1H), 7.74 (s, 1H), 4.39 (s, 2H), 1.65 (s, 9H)

Workup

  1. temperaturethe reaction mixture 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-021d9246c5b340a9a04c6e02e860b52b
Source dataset
uspto-grants-2006_06
Patent number
US07067540B2

Reaction notes

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