Reaction #172393

ord-0ef82594ae314ca48f28cdfe6e947d73

Conditions

Detailed conditions
See reaction.notes.procedure_details.

Workup

  1. 1
    Temperaturethe mixture is heated
  2. 2
    Temperatureunder reflux
  3. 3
    Temperatureto cool
  4. 4
    Filtrationfiltered
  5. 5
    Otherevaporated to dryness under reduced pressure
  6. 6
    workup.DISSOLUTIONThe residue is dissolved in 300 ml of dichloromethane
  7. 7
    workup.ADDITION300 g of sea sand are added
  8. 8
    ConcentrationOnce more, the mixture is then concentrated to dryness under reduced pressure
  9. 9
    OtherThe product is chromatographed
  10. 10
    workup.ADDITIONa 20:1 mixture of cyclohexane and ethyl acetate
  11. 11
    Otherthe product fractions are evaporated to dryness under reduced pressure
  12. 12
    OtherThe residue is crystallized with cyclohexane
  13. 13
    Otherdried under reduced pressure

Procedure

186 g (1.20 mol) of 2-fluoro-5-nitrotoluene are dissolved in 1.2 l of carbon tetrachloride, and 214 g (1.20 mol) of N-bromosuccinimide are added. 19.7 g (120 mmol) of azodiisobutyronitrile are added, and the mixture is heated under reflux. After 16 h, the mixture is allowed to cool, filtered and evaporated to dryness under reduced pressure. The residue is dissolved in 300 ml of dichloromethane, and 300 g of sea sand are added. Once more, the mixture is then concentrated to dryness under reduced pressure, and the residue is applied to a 1 kg silica gel column. The product is chromatographed using a 20:1 mixture of cyclohexane and ethyl acetate, and the product fractions are evaporated to dryness under reduced pressure. The residue is crystallized with cyclohexane and dried under reduced pressure. This gives 92 g (32% of theory) of the desired product.

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08846934B2uspto-grants-2014_09