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

HRID 2209561Notes

Reaction equation

HRID 2209561 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 witch 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.; IR (nujol) 2255, 2245 cm-1 (CN) 13C NMR (DMSO-d6) 102.7 (N-CN), 113.7 (3-CN); Mass spectrum 331.9 (M+1).

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 witch 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-8117eb166e214ae79272083d1b629f62
Source dataset
uspto-grants-1995_10
Patent number
US05455263

Reaction notes

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