Dimethylcarbamoyl Chloride → 3,5-Dibromopicolinonitrile

HRID 1352766Notes

Reaction equation

HRID 1352766 reaction equation
[Br:1][C:2]1[CH:3]=[N+:4]([O-])[CH:5]=[C:6]([Br:8])[CH:7]=1.C[Si]([C:14]#[N:15])(C)C.CN(C)C(Cl)=O.C(=O)([O-])O.[Na+]>C(Cl)Cl>[C:14]([C:3]1[C:2]([Br:1])=[CH:7][C:6]([Br:8])=[CH:5][N:4]=1)#[N:15]

Participants

6

Reactant 4

HCID 6598Dimethylcarbamoyl Chloride2×HCID 82115Trimethylsilyl cyanide2×HCID 516892Sodium BicarbonateHCID 6200033,5-Dibromopyridine 1-oxide

Product 1

HCID 123612023,5-Dibromopicolinonitrile

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A mixture of 3,5-dibromopyridine N-oxide (prepared in the above (1)) 2.26 g, trimethylsilylcyanide 1.06 g and dimethylcarbamic acid chloride 1.15 g in methylene chloride 25 ml is refluxed under heating for 1 day. To the mixture are added trimethylsilylcyanide 443 mg and dimethylcarbamic acid chloride 480 mg, and the mixture is refluxed under heating for 20 hours. An aqueous sodium hydrogen carbonate solution is added to the reaction mixture cooled, and the mixture is extracted with methylene chloride. The combined extract is washed, dried and the solvent is removed in vacuo. The residue is purified by silica gel chromatography (solvent; n-hexane:ethyl acetate=1:1) to give 2-cyano-3,5-dibromopyridine 1.38 g. mp 109–112° C.

Workup

  1. temperatureis refluxed
  2. temperatureunder heating for 1 day
  3. temperaturethe mixture is refluxed
  4. temperatureunder heating for 20 hours
  5. temperaturecooled
  6. extractionthe mixture is extracted with methylene chloride
  7. extractionThe combined extract
  8. washis washed
  9. customdried
  10. customthe solvent is removed in vacuo
  11. customThe residue is purified by silica gel chromatography (solvent; n-hexane:ethyl acetate=1:1)

Sources & evidence

ORD record
ord-df90a6878b634bb2a9f7b39a50c7460e
Source dataset
uspto-grants-2007_05
Patent number
US07220736B2

Reaction notes

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