5-Bromo-4-chlorothiophene-2-sulfonamide → 4-Chlorothiophene-2-sulfonamide

HRID 6959Notes

Reaction equation

HRID 6959 reaction equation
Br[C:2]1[S:6][C:5]([S:7]([NH2:10])(=[O:9])=[O:8])=[CH:4][C:3]=1[Cl:11]>CC(O)=O.[Zn]>[Cl:11][C:3]1[CH:4]=[C:5]([S:7]([NH2:10])(=[O:9])=[O:8])[S:6][CH:2]=1

Participants

4

Reactant 1

HCID 27400625-Bromo-4-chlorothiophene-2-sulfonamide

Product 1

HCID 220194654-Chlorothiophene-2-sulfonamideYield 52%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 176Acetic AcidSolvent

Conditions

Temperature
120 °C

Procedure

To a stirred solution of 5-bromo-4-chlorothiophene-2-sulfonamide (2.4 g, 8.7 mmol) in AcOH (20 mL) is added zinc dust (1.7 g, 26.0 mmol). The reaction mixture is heated to 120° C. for 6 hr. After 6 hr, the mixture is filtered and neutralized with 1 M NaOH. The aqueous layer is extracted with EtOAc (2×100 mL). The combined organic extracts are dried (Na2SO4), filtered and concentrated in vacuo. The crude product is chromatographed on silica gel, eluting with CH2Cl2 to afford the title compound (0.88 g, 52%).

Workup

  1. filtrationthe mixture is filtered
  2. extractionThe aqueous layer is extracted with EtOAc (2×100 mL)
  3. dry with materialThe combined organic extracts are dried (Na2SO4)
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customThe crude product is chromatographed on silica gel
  7. washeluting with CH2Cl2

Sources & evidence

ORD record
ord-ee96dca7353343b0ab451e1a1c0600f7
Source dataset
uspto-grants-2006_08
Patent number
US07084170B2

Reaction notes

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