Réaction #1447105

Équation de réaction

N-Iodosuccinimide

3-bromo-2-methyl-benzoic acid

→

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

Solvants

sulphuric acid

sulphuric acid

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONis added at such a rate that the solution temperature
2. 2
   Températuremaintained below 5° C
3. 3
   Températurebefore warming to room temperature over night
4. 4
   workup.ADDITIONThen, the mixture is poured
5. 5
   Extractionthe resultant solution is extracted with ethyl acetate
6. 6
   LavageThe combined extracts are washed in succession with aqueous 10% Na2S2O3 solution (2×), water (3×), and brine (1×)
7. 7
   SéchageAfter drying (MgSO4) the organic layer
8. 8
   Autrethe solvent is evaporated under reduced pressure
9. 9
   Autreto give a solid
10. 10
    AutreThe solid is triturated with 70° C.-
11. 11
    Températurewarm water
12. 12
    Autreseparated from the water by filtration
13. 13
    Autredried
14. 14
    AutreAfter the solid is triturated with little ether
15. 15
    Filtrationfiltered
16. 16
    Autredried
17. 17
    Autrethe product is obtained as a white solid

Mode opératoire

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.

Source