Reaktion #172393

Reaktionsgleichung

2-fluoro-5-nitrotoluene

N-bromosuccinimide

azodiisobutyronitrile

→

2-(Bromomethyl)-1-fluoro-4-nitrobenzene

Lösungsmittel

carbon tetrachloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture is heated
2. 2
   Temperaturunder reflux
3. 3
   Temperaturto cool
4. 4
   Filtrationfiltered
5. 5
   Sonstigeevaporated 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
   EinengenOnce more, the mixture is then concentrated to dryness under reduced pressure
9. 9
   SonstigeThe product is chromatographed
10. 10
    workup.ADDITIONa 20:1 mixture of cyclohexane and ethyl acetate
11. 11
    Sonstigethe product fractions are evaporated to dryness under reduced pressure
12. 12
    SonstigeThe residue is crystallized with cyclohexane
13. 13
    Sonstigedried under reduced pressure

Vorschrift

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.

Quelle