Diphosgene → 1-Bromo-4-isocyanato-2-(trifluoromethyl)benzene

HRID 1768297Notes

Reaction equation

HRID 1768297 reaction equation
Cl.[Br:2][C:3]1[CH:9]=[CH:8][C:6]([NH2:7])=[CH:5][C:4]=1[C:10]([F:13])([F:12])[F:11].Cl[C:15](OC(Cl)(Cl)Cl)=[O:16]>C1(C)C=CC=CC=1>[Br:2][C:3]1[CH:9]=[CH:8][C:6]([N:7]=[C:15]=[O:16])=[CH:5][C:4]=1[C:10]([F:11])([F:12])[F:13]

Participants

4

Reactant 2

HCID 10426DiphosgeneHCID 667457074-bromo-3-(trifluoromethyl)aniline HCl salt

Product 1

HCID 231372171-Bromo-4-isocyanato-2-(trifluoromethyl)benzeneYield 86%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A suspension of 4-bromo-3-(trifluoromethyl)aniline HCl salt (36.8 g, 133 mmol) in toluene (278 mL) was treated with trichloromethyl chloroformate dropwise and the resulting mixture was heated at the reflux temp. for 18 h. The resulting mixture was concentrated under reduced pressure. The residue was treated with toluene (500 mL), then concentrated under reduced pressure. The residue was treated with CH2Cl2 (500 mL), then concentrated under reduced pressure. The CH2Cl2 treatment/concentration protocol was repeated and resulting amber oil was stored at −20° C. for 16 h, to afford 4-bromo-3-(trifluoromethyl)phenyl isocyanate as a tan solid (35.1 g, 86%): GC-MS m/z 265 (M+).

Workup

  1. temperaturethe resulting mixture was heated at the reflux temp
  2. concentrationThe resulting mixture was concentrated under reduced pressure
  3. additionThe residue was treated with toluene (500 mL)
  4. concentrationconcentrated under reduced pressure
  5. additionThe residue was treated with CH2Cl2 (500 mL)
  6. concentrationconcentrated under reduced pressure
  7. concentrationThe CH2Cl2 treatment/concentration protocol
  8. customresulting amber oil
  9. waitwas stored at −20° C. for 16 h

Sources & evidence

ORD record
ord-0a4f55bf708246cca576a63dd1f78a21
Source dataset
uspto-grants-2007_06
Patent number
US07235576B1

Reaction notes

Loading…