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

186 g (1.2 mol) of 2-fluoro-5-nitrotoluene are dissolved in 1.2 l of tetrachloromethane and admixed with 214 g (1.20 mol) of N-bromosuccinimide. 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 concentrated to dryness under reduced pressure. The residue is dissolved in 300 ml of dichloromethane and admixed with 300 g of Seesand. Then the mixture is concentrated to dryness under reduced pressure again, and the residue is applied to a 1 kg silica gel column. It is chromatographed with a 20:1 mixture of cyclohexane and ethyl acetate, and the product fractions are concentrated to dryness under reduced pressure. The residue is crystallized with cyclohexane and dried under reduced pressure. This affords 92 g (32% of theory) of the desired product.

1. temperaturethe mixture is heated
2. temperatureunder reflux
3. temperatureto cool
4. filtrationfiltered
5. concentrationconcentrated to dryness under reduced pressure
6. dissolutionThe residue is dissolved in 300 ml of dichloromethane
7. concentrationThen the mixture is concentrated to dryness under reduced pressure again
8. customIt is chromatographed with a 20:1 mixture of cyclohexane and ethyl acetate
9. concentrationthe product fractions are concentrated to dryness under reduced pressure
10. customThe residue is crystallized with cyclohexane
11. customdried under reduced pressure

ORD record

ord-35e4023624a54c4792ad21302530523f

Source dataset

uspto-grants-2012_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08198267B2