Bromine → 1H-Pyrazole, 3-(bromomethyl)-5-chloro-1-methyl-4-nitro-

HRID 1085161Notes

Reaction equation

HRID 1085161 reaction equation
[Cl:1][C:2]1[N:6]([CH3:7])[N:5]=[C:4]([CH3:8])[C:3]=1[N+:9]([O-:11])=[O:10].[Br:12]Br>C(Cl)(Cl)(Cl)Cl>[Br:12][CH2:8][C:4]1[C:3]([N+:9]([O-:11])=[O:10])=[C:2]([Cl:1])[N:6]([CH3:7])[N:5]=1

Participants

4

Reactant 2

HCID 24408Bromine2×HCID 2795155-Chloro-1,3-dimethyl-4-nitro-1H-pyrazole

Product 1

HCID 102643161H-Pyrazole, 3-(bromomethyl)-5-chloro-1-methyl-4-nitro-

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

5-Chloro-1,3-dimethyl-4-nitropyrazole (43 g, 0.29 moles) was dissolved in carbon tetrachloride (430 ml), bromine (12 ml) was added and the reaction mixture stirred at reflux for 48 hours whilst illuminating with a 500 W light source. A second portion of bromine (12 ml) was added and the reaction mixture refluxed for a further 48 hours. The reaction mixture was cooled and chromatographed on silica (gradient elution commencing with hexane and increasing the proportion of dichloromethane from 0 to 100%). Fractions containing the product were evaporated yielding the title compound as a white solid. (35 g. 47%)

Workup

  1. temperatureat reflux for 48 hours
  2. customwhilst illuminating with a 500 W light source
  3. temperaturethe reaction mixture refluxed for a further 48 hours
  4. temperatureThe reaction mixture was cooled
  5. customchromatographed on silica (
  6. washgradient elution
  7. temperatureincreasing the proportion of dichloromethane from 0 to 100%)
  8. additionFractions containing the product
  9. customwere evaporated

Sources & evidence

ORD record
ord-45a30ca7a0d54bd9ac003920bd6fe2d6
Source dataset
uspto-grants-1991_04
Patent number
US05008263

Reaction notes

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