1H-Pyrazole-4-carbonitrile → 1-(3-bromo-2-formylphenyl)-1H-pyrazole-4-carbonitrile

HRID 1025613Notes

Reaction equation

HRID 1025613 reaction equation
[NH:1]1[CH:5]=[C:4]([C:6]#[N:7])[CH:3]=[N:2]1.CC(C)([O-])C.[K+].[Br:14][C:15]1[CH:22]=[CH:21][CH:20]=[C:19](F)[C:16]=1[CH:17]=[O:18]>CS(C)=O>[Br:14][C:15]1[C:16]([CH:17]=[O:18])=[C:19]([N:1]2[CH:5]=[C:4]([C:6]#[N:7])[CH:3]=[N:2]2)[CH:20]=[CH:21][CH:22]=1

Participants

5

Reactant 3

HCID 5644491H-Pyrazole-4-carbonitrileHCID 224739772-Bromo-6-fluorobenzaldehydeHCID 23665647Potassium tert-butoxide

Product 1

HCID 866737221-(3-bromo-2-formylphenyl)-1H-pyrazole-4-carbonitrileYield 55.4%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

1H-pyrazole-4-carbonitrile (935 mg, 10.0 mmol, Eq: 1.00) was dissolved in 15 mL of dry DMSO and potassium tert-butoxide (1.19 g, 10.0 mmol, Eq: 1.00) was added. The mixture was stirred at room temperature for 20 minutes and 2-bromo-6-fluorobenzaldehyde (4.08 g, 20.1 mmol, Eq: 2) was added. The mixture was stirred at room temperature overnight and then extracted with ethyl acetate and water. The organic layer was dried and concentrated. The crude material was purified by flash chromatography (silica gel, 40 g, 20% to 40% EtOAc in hexanes) to give 1-(3-bromo-2-formylphenyl)-1H-pyrazole-4-carbonitrile (1.53 g, 55%).

Workup

  1. stirringThe mixture was stirred at room temperature overnight
  2. extractionextracted with ethyl acetate and water
  3. customThe organic layer was dried
  4. concentrationconcentrated
  5. customThe crude material was purified by flash chromatography (silica gel, 40 g, 20% to 40% EtOAc in hexanes)

Sources & evidence

ORD record
ord-1b1df8405c7e4ab285cb26745765008d
Source dataset
uspto-grants-2014_05
Patent number
US08729078B2

Reaction notes

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