Hydrochloric Acid → 4-bromo-1-(2-ethoxyethyl)-1H-pyrazole

HRID 877906Notes

Reaction equation

HRID 877906 reaction equation
[Br:1][C:2]1[CH:3]=[N:4][NH:5][CH:6]=1.Cl.[CH:8]([O:10][CH2:11][CH3:12])=[CH2:9]>C(Cl)Cl.O1CCOCC1>[Br:1][C:2]1[CH:3]=[N:4][N:5]([CH2:9][CH2:8][O:10][CH2:11][CH3:12])[CH:6]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 8023Ethyl vinyl etherHCID 163754-Bromopyrazole

Product 1

HCID 518921394-bromo-1-(2-ethoxyethyl)-1H-pyrazoleYield 108.4%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 312751,4-DioxaneSolvent

Procedure

To a solution of 4-bromopyrazole (70.0 g, 0.476 mol) in CH2Cl2 (600 mL) was added a solution of 3.1 M HCl in dioxane (4 mL) and ethyl vinyl ether (41 g, 0.569 mol, 1.2 equiv) at ambient temperature. The resulting reaction mixture was stirred at ambient temperature for 3 h. The reaction was quenched with aqueous NaHCO3 and the two layers were separated. The organic layer was washed with water, dried over Na2SO4, and concentrated under reduced pressure to dryness to afford 4-bromo-1-(ethoxyethyl)-1H-pyrazole (113 g, 104.3 g theoretical, 97% yield) as an oil (GC purity: 89%), which was directly used in the subsequent reaction without further purification.

Workup

  1. customThe resulting reaction mixture
  2. customThe reaction was quenched with aqueous NaHCO3
  3. customthe two layers were separated
  4. washThe organic layer was washed with water
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated under reduced pressure to dryness

Sources & evidence

ORD record
ord-da127379ba584366a556a5f68003dbfa
Source dataset
uspto-grants-2015_03
Patent number
US08987443B2

Reaction notes

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