Propargyl bromide → 4-Chloro-1-(2,4-dichloro-5-prop-2-ynoxyphenyl)-3,5-dimethylpyrazole

HRID 580264Notes

Reaction equation

HRID 580264 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[C:5]([OH:9])=[CH:4][C:3]=1[N:10]1[C:14]([CH3:15])=[C:13]([Cl:16])[C:12]([CH3:17])=[N:11]1.[CH2:18](Br)[C:19]#[CH:20].C[O-].[Na+].[Na]>C1(C)C=CC=CC=1.O.CO>[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[C:5]([O:9][CH2:20][C:19]#[CH:18])=[CH:4][C:3]=1[N:10]1[C:14]([CH3:15])=[C:13]([Cl:16])[C:12]([CH3:17])=[N:11]1

Participants

8

Reactant 4

HCID 7842Propargyl bromideHCID 5360545SodiumHCID 10942334Sodium MethoxideHCID 13798309HCID 13798309, compound

Product 1

HCID 1846184-Chloro-1-(2,4-dichloro-5-prop-2-ynoxyphenyl)-3,5-dimethylpyrazoleYield 91.2%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 1140TolueneSolvent2×

Procedure

1-(2,4-dichloro-5-hydroxyphenyl)-3,5-dimethyl-4-chloropyrazole (29.2 g) and propargyl bromide (12.0 g) were added to a solution of sodium methoxide which was previously prepared from metallic sodium (2.3 g) and methanol (200 ml). The resulting mixture was heated under reflux, with stirring for 3 hours. To the reaction mixture, after cooling, were added water and toluene to form two layers. The toluene layer as formed was separated, washed with water and then dried over anhydrous sodium sulfate. Removal of the solvent by distillation in vacuo gave the titled compound (30.1 g) as a pale brown crystalline solid. Recrystallization of this solid from a mixture of cyclohexane/acetone afforded a white crystalline solid. m.p. 156.5°-158° C.

Workup

  1. temperatureThe resulting mixture was heated
  2. temperatureunder reflux
  3. temperatureTo the reaction mixture, after cooling
  4. customto form two layers
  5. customwas separated
  6. washwashed with water
  7. dry with materialdried over anhydrous sodium sulfate
  8. customRemoval of the solvent
  9. distillationby distillation in vacuo

Sources & evidence

ORD record
ord-829d181ad0bd40dfb73e4697ba444424
Source dataset
uspto-grants-1988_06
Patent number
US04752326

Reaction notes

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