Benzene → 3-Bromo-2-chloro-4,5-difluorobenzonitrile

HRID 2232650Notes

Reaction equation

HRID 2232650 reaction equation
F[B-](F)(F)F.[Br:6][C:7]1[C:8]([Cl:17])=[C:9]([N+]#N)[CH:10]=[C:11]([F:14])[C:12]=1[F:13].[C-:18]#[N:19].[K+].C(=O)([O-])[O-].[Na+].[Na+].C1C=CC=CC=1>O>[Br:6][C:7]1[C:8]([Cl:17])=[C:9]([CH:10]=[C:11]([F:14])[C:12]=1[F:13])[C:18]#[N:19]

Participants

6

Reactant 4

HCID 241BenzeneHCID 9032Potassium CyanideHCID 10340Sodium CarbonateHCID 143652533-Bromo-2-chloro-4,5-difluorobenzenediazonium tetrafluoroborate

Product 1

HCID 140717963-Bromo-2-chloro-4,5-difluorobenzonitrileYield 41.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

3-Bromo-2-chloro-4,5-difluorobenzenediazonium tetrafluoroborate (35.6 g) was added portionwise during 40 minutes to a solution of cuprous cyanide (18.67 g), potassium cyanide (27.14 g) and sodium carbonate (5.52 g) in water (200 ml) with stirring vigorously at room temperature. After the mixture was stirred for 4.5 hours, benzene (250 ml) was added to the suspension and then the mixture was stirred for 25 minutes. The insoluble materials were collected by filtration, and washed with benzene. The filtrate and washings were combined and washed with water, dried over anhydrous sodium sulfate and then concentrated. The resulting residue was purified by silica gel chromatography eluting with dichloromethane-n-hexane (1:3) and further recrystallized from n-hexane-dichloromethane to give the title compound (10.9 g) as light yellow needles, mp 71°-72.5° C.

Workup

  1. stirringAfter the mixture was stirred for 4.5 hours
  2. stirringthe mixture was stirred for 25 minutes
  3. filtrationThe insoluble materials were collected by filtration
  4. washwashed with benzene
  5. washwashed with water
  6. dry with materialdried over anhydrous sodium sulfate
  7. concentrationconcentrated
  8. customThe resulting residue was purified by silica gel chromatography
  9. washeluting with dichloromethane-n-hexane (1:3)
  10. customfurther recrystallized from n-hexane-dichloromethane

Sources & evidence

ORD record
ord-8dfe79a4c4b2492082cbdb6da922054e
Source dataset
uspto-grants-1988_11
Patent number
US04788320

Reaction notes

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