N-bromobutanimide → 4-Chloro-5-fluoro-alpha-bromo-2-picoline

Temperatur

75 °C

4-Chloro-5-fluoro-2-picoline (2.9 g, 20 mmol), the product of Example 66, was dissolved in 50 mL of 1,2-dichloroethane in a dry flask. The resultant solution was heated, with stirring, to 75° C. and 4.09 (23 mmol) of N-bromosuccinimide was added, followed by 100 mG (0.7 mmol) of 2,2-azobisisobutyronitrile (AIBN), a free radical initiator. After the reaction mixture was stirred at 75° C. for 24 hours, it was diluted with 450 mL of methylene chloride and washed with 3×400 mL of water. The organic layer was separated and dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was dried in vacuo to give 3.5 g (69% yield) of the title compound as an amber oil; 1H NMR (CDCl3) d 4.50 (s, 2H), 7.54 (d, 1H), 8.44 (s, 1H).

1. stirringAfter the reaction mixture was stirred at 75° C. for 24 hours
2. washwashed with 3×400 mL of water
3. customThe organic layer was separated
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customThe residue was dried in vacuo

ORD-Eintrag

ord-f274be8d731f425884197cae074e7e36

Quelldatensatz

uspto-grants-1996_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05580872