Reaction #1447105

Reaction equation

N-Iodosuccinimide

3-bromo-2-methyl-benzoic acid

→

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

Solvents

sulphuric acid

sulphuric acid

Conditions

Workup

1. 1
   workup.ADDITIONis added at such a rate that the solution temperature
2. 2
   Temperaturemaintained below 5° C
3. 3
   Temperaturebefore 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
   WashThe combined extracts are washed in succession with aqueous 10% Na2S2O3 solution (2×), water (3×), and brine (1×)
7. 7
   DryingAfter drying (MgSO4) the organic layer
8. 8
   Otherthe solvent is evaporated under reduced pressure
9. 9
   Otherto give a solid
10. 10
    OtherThe solid is triturated with 70° C.-
11. 11
    Temperaturewarm water
12. 12
    Otherseparated from the water by filtration
13. 13
    Otherdried
14. 14
    OtherAfter the solid is triturated with little ether
15. 15
    Filtrationfiltered
16. 16
    Otherdried
17. 17
    Otherthe product is obtained as a white solid

Procedure

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