Cyanogen Bromide → 4,5-Dichloro-2-(3,4-dichlorophenyl)pyrrole-1,3-dicarbonitrile

HRID 1651691Notes

Reaction equation

HRID 1651691 reaction equation
CC(C)([O-])C.[K+].[C:7]([C:9]1[C:13]([Cl:14])=[C:12]([Cl:15])[NH:11][C:10]=1[C:16]1[CH:21]=[CH:20][C:19]([Cl:22])=[C:18]([Cl:23])[CH:17]=1)#[N:8].[N:24]#[C:25]Br>C1COCC1>[Cl:14][C:13]1[C:9]([C:7]#[N:8])=[C:10]([C:16]2[CH:21]=[CH:20][C:19]([Cl:22])=[C:18]([Cl:23])[CH:17]=2)[N:11]([C:25]#[N:24])[C:12]=1[Cl:15]

Participants

5

Reactant 3

HCID 10476Cyanogen BromideHCID 1835554,5-dichloro-2-(3,4-dichlorophenyl)-1H-pyrrole-3-carbonitrileHCID 23665647Potassium tert-butoxide

Product 1

HCID 150101564,5-Dichloro-2-(3,4-dichlorophenyl)pyrrole-1,3-dicarbonitrileYield 64.7%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

Potassium t-butoxide (617 mg, 55 mmol) is added in portions to a solution of 3-cyano-4,5-dichloro-2-(3,4-dichlorophenyl)pyrrole (1.52 g, 5 mmol) in anhydrous THF (20 mL). After 30 minutes, a solution of cyanogen bromide (583 mg, 5.5 mmol) in THF (1 mL) is added. The reaction mixture is stored at room temperature overnight. The solvent is removed in a rotary evaporator. The residue is treated with water and extracted with ethyl acetate. The organic layer is washed with water and saturated sodium chloride and dried (MgSO4). Evaporation and crystallization of the residue from ethyl acetate gives while crystals (1.07 g); mp 250.5°-252.0° C.

Workup

  1. waitThe reaction mixture is stored at room temperature overnight
  2. customThe solvent is removed in a rotary evaporator
  3. additionThe residue is treated with water
  4. extractionextracted with ethyl acetate
  5. washThe organic layer is washed with water and saturated sodium chloride
  6. dry with materialdried (MgSO4)
  7. customEvaporation and crystallization of the residue from ethyl acetate

Sources & evidence

ORD record
ord-c4eb45677bcc466f9b5786109ecfbfb7
Source dataset
uspto-grants-1990_05
Patent number
US04929634

Reaction notes

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