Reaktion #1447105

Reaktionsgleichung

N-Iodosuccinimide

3-bromo-2-methyl-benzoic acid

→

3-Bromo-5-iodo-2-methyl-benzoic acid

Lösungsmittel

sulphuric acid

sulphuric acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONis added at such a rate that the solution temperature
2. 2
   Temperaturmaintained below 5° C
3. 3
   Temperaturbefore warming to room temperature over night
4. 4
   workup.ADDITIONThen, the mixture is poured
5. 5
   Extraktionthe resultant solution is extracted with ethyl acetate
6. 6
   WaschenThe combined extracts are washed in succession with aqueous 10% Na2S2O3 solution (2×), water (3×), and brine (1×)
7. 7
   TrocknenAfter drying (MgSO4) the organic layer
8. 8
   Sonstigethe solvent is evaporated under reduced pressure
9. 9
   Sonstigeto give a solid
10. 10
    SonstigeThe solid is triturated with 70° C.-
11. 11
    Temperaturwarm water
12. 12
    Sonstigeseparated from the water by filtration
13. 13
    Sonstigedried
14. 14
    SonstigeAfter the solid is triturated with little ether
15. 15
    Filtrationfiltered
16. 16
    Sonstigedried
17. 17
    Sonstigethe product is obtained as a white solid

Vorschrift

N-Iodosuccinimide (5.8 g) is added in portions to an ice-cold solution of sulphuric acid (20 mL). The resulting mixture is stirred for 40 min before 3-bromo-2-methyl-benzoic acid (5.0 g) dissolved in sulphuric acid (20 mL) is added at such a rate that the solution temperature maintained below 5° C. The mixture is stirred at 5-10° C. for another 3 h before warming to room temperature over night. Then, the mixture is poured on crushed ice (300 g) and the resultant solution is extracted with ethyl acetate. The combined extracts are washed in succession with aqueous 10% Na2S2O3 solution (2×), water (3×), and brine (1×). After drying (MgSO4) the organic layer, the solvent is evaporated under reduced pressure to give a solid. The solid is triturated with 70° C.-warm water, separated from the water by filtration and dried. After the solid is triturated with little ether, filtered and dried, the product is obtained as a white solid.

Quelle