Réaction #2028942

Équation de réaction

Methanesulfonyl chloride

methanesulfonyl chloride

4-bromo-3-chloroaniline

H2O

→

desired product

N-(4-bromo-3-chlorophenyl)methanesulfonamide

Solvants

pyridine

Conditions de réaction

Traitement

1. 1
   Températurecooling
2. 2
   AutreThe ice bath was removed immediately
3. 3
   workup.ADDITIONafter addition of the reagent
4. 4
   workup.STIRRINGAfter stirring for 0.5 h
5. 5
   Extractionextracted with EtOAc (50 mL×3)
6. 6
   LavageCombined organic layers were washed with brine (50 mL×2)
7. 7
   Séchagedried over Na2SO4
8. 8
   AutreThe solvent was removed in vacuo
9. 9
   Autreto give the crude material (very light brown solid, 5.32 g)
10. 10
    AutreThe crude product was purified by a silica gel column chromatography (SiO2=80 g, EtOAc/hexane=1:1, Rf=0.3)

Mode opératoire

In a 100 mL round bottomed flask 4-bromo-3-chloroaniline (A, 2.06 g, 10.0 mmol) was dissolve in pyridine (30 mL) at room temperature. Methanesulfonyl chloride (1.72 g, 15.0 mmol, 1.5 equiv) was added under an ice-water bath cooling. The ice bath was removed immediately after addition of the reagent. After stirring for 1.5 h, another methanesulfonyl chloride (0.57 g, 5.0 mmol, 0.5 equiv) was added at room temperature for the reaction to go to completion. After stirring for 0.5 h, the mixture was treated with H2O (50 mL) and extracted with EtOAc (50 mL×3). Combined organic layers were washed with brine (50 mL×2) and dried over Na2SO4. The solvent was removed in vacuo to give the crude material (very light brown solid, 5.32 g). The crude product was purified by a silica gel column chromatography (SiO2=80 g, EtOAc/hexane=1:1, Rf=0.3) to give the desired product as colorless crystals. The obtained crystals were recrystallized from EtOAc/hexane=1:2 (24 mL) to give the desired material [N-(4-bromo-3-chlorophenyl)methanesulfonamide (B)].

Source