Chlorosulfonic acid → Imidazo[1,2-a]pyridine-3-sulfonic acid

HRID 2374137Notes

Reaction equation

HRID 2374137 reaction equation
Cl[S:2]([OH:5])(=[O:4])=[O:3].[N:6]1[CH:7]=[CH:8][N:9]2[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=12>C(Cl)(Cl)Cl>[N:6]1[CH:7]=[C:8]([S:2]([OH:5])(=[O:4])=[O:3])[N:9]2[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=12

Participants

4

Reactant 2

HCID 24638Chlorosulfonic acidHCID 78960Imidazo(1,2-a)pyridine

Product 1

HCID 14422414Imidazo[1,2-a]pyridine-3-sulfonic acidYield 0.1%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent2×

Procedure

Chlorosulfonic acid (0.170 mL, 2.55 mmol) was dissolved in chloroform (1 mL) and this solution was added dropwise to imidazo[1,2-a]-pyridine (0.100 g, 0.85 mmol) in chloroform (4 mL) over 10 min. The reaction mixture was heated to reflux for 24 h, then allowed to cool to RT and concentrated to dryness under vacuum. The crude oily product was treated with diethyl ether (10 mL) and ethanol (5 mL) resulting in a white precipitate. The solid was collected by filtration, washed with EtOH and dried to yield imidazo[1,2-a]-pyridine-3-sulfonic acid (0.128 mg). MS (ESI−) for m/z 131 (M−H)−.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 24 h
  3. concentrationconcentrated to dryness under vacuum
  4. additionThe crude oily product was treated with diethyl ether (10 mL) and ethanol (5 mL)
  5. customresulting in a white precipitate
  6. filtrationThe solid was collected by filtration
  7. washwashed with EtOH
  8. customdried

Sources & evidence

ORD record
ord-2391bd5903ea420391470e1196ab210c
Source dataset
uspto-grants-2008_12
Patent number
US07462600B2

Reaction notes

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