Reacción #1447105

Ecuación de reacción

N-Iodosuccinimide

3-bromo-2-methyl-benzoic acid

→

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

Disolventes

sulphuric acid

sulphuric acid

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONis added at such a rate that the solution temperature
2. 2
   Temperaturamaintained below 5° C
3. 3
   Temperaturabefore warming to room temperature over night
4. 4
   workup.ADDITIONThen, the mixture is poured
5. 5
   Extracciónthe resultant solution is extracted with ethyl acetate
6. 6
   LavadoThe combined extracts are washed in succession with aqueous 10% Na2S2O3 solution (2×), water (3×), and brine (1×)
7. 7
   SecadoAfter drying (MgSO4) the organic layer
8. 8
   Otrothe solvent is evaporated under reduced pressure
9. 9
   Otroto give a solid
10. 10
    OtroThe solid is triturated with 70° C.-
11. 11
    Temperaturawarm water
12. 12
    Otroseparated from the water by filtration
13. 13
    Otrodried
14. 14
    OtroAfter the solid is triturated with little ether
15. 15
    Filtraciónfiltered
16. 16
    Otrodried
17. 17
    Otrothe product is obtained as a white solid

Procedimiento

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.

Fuente