Chlorosulfonic acid → 2-Ethylthieno[2,3-b]pyridine-3-sulfonyl chloride

HRID 2268981Notes

Reaction equation

HRID 2268981 reaction equation
[CH2:1]([C:3]1[S:11][C:6]2=[N:7][CH:8]=[CH:9][CH:10]=[C:5]2[CH:4]=1)[CH3:2].[Cl:12][S:13](O)(=[O:15])=[O:14].P(Cl)(Cl)(Cl)=O.P(Cl)(Cl)(Cl)(Cl)Cl>C(Cl)Cl>[CH2:1]([C:3]1[S:11][C:6]2=[N:7][CH:8]=[CH:9][CH:10]=[C:5]2[C:4]=1[S:13]([Cl:12])(=[O:15])=[O:14])[CH3:2]

Participants

6

Reactant 4

HCID 24638Chlorosulfonic acidHCID 24813Phosphorus oxychlorideHCID 24819Phosphorus pentachlorideHCID 120449142-Ethylthieno[2,3-b]pyridine

Product 1

HCID 120449152-Ethylthieno[2,3-b]pyridine-3-sulfonyl chlorideYield 57.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2-ethylthieno[2,3-b]pyridine (0.43 g, 2.6 mmoles) in CH2Cl2 (10 ml) at −78° C. was added chlorosulfonic acid (0.9 ml, 13 mmoles). The reaction was warmed to ambient temperature over a 1 hr. period, then stirred an additional 20 hrs., followed by the addition of phosphorus oxychloride (1.7 ml, 18 mmoles) and phosphorus pentachloride (0.82 g, 4.0 mmoles). One hour later the reaction mixture was added to ice (100 ml) and extracted with EtOAc (75 ml), then washed with sat. NaHCO3 (200 ml). The organic phase was dried (MgSO4), filtered and concentrated to collect a brown oil. Flash chromatography (10% EtOAc/hexanes) provided 0.39 g (56%) of the title compound as a light yellow oil.

Workup

  1. extractionextracted with EtOAc (75 ml)
  2. washwashed with sat. NaHCO3 (200 ml)
  3. dry with materialThe organic phase was dried (MgSO4)
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customto collect a brown oil

Sources & evidence

ORD record
ord-632d16e2f47a473a91a2523fcd324367
Source dataset
uspto-grants-2001_12
Patent number
US06329387B2

Reaction notes

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