Pyridinium chloride → 5-Hydroxy-1H-indole-2-sulfonamide

HRID 1904951Notes

Reaction equation

HRID 1904951 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][C:7]([S:12](=[O:15])(=[O:14])[NH2:13])=[CH:6]2.Cl.N1C=CC=CC=1>>[OH:2][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][C:7]([S:12](=[O:14])(=[O:15])[NH2:13])=[CH:6]2

Participants

3

Reactant 2

HCID 10176127Pyridinium chlorideHCID 14476489HCID 14476489, compound

Product 1

HCID 144764915-Hydroxy-1H-indole-2-sulfonamideYield 102.8%

Conditions

Temperature
190 °C

Procedure

5-Methoxy-2-sulfamoyl-1H-indole (2.5 gm, 11 mmol) was mixed with pyridine hydrochloride (7.5 gm) and heated neat at 190° C. for 30 minutes. The reaction was cooled to 140° C. and poured onto ice water (25 gm). The mixture was extracted with ethyl acetate (3×100 ml), washed with water (2×50 ml), brine (2×25 ml) and dried (MgSO4). The ethyl acetate was removed under vacuum to yield a brown solid 2.4 gm. The solid was flash chromatographed using silica gel with 95/5 (V/V) chloroform-methanol. The isolated compound was crystallized using chloroform-methanol 95/5 (V/V) to yield a white solid; 628 mg., m.p. 220°-221° C. (dec).

Workup

  1. temperatureThe reaction was cooled to 140° C.
  2. additionpoured onto ice water (25 gm)
  3. extractionThe mixture was extracted with ethyl acetate (3×100 ml)
  4. washwashed with water (2×50 ml), brine (2×25 ml)
  5. dry with materialdried (MgSO4)
  6. customThe ethyl acetate was removed under vacuum

Sources & evidence

ORD record
ord-20b7c3e09f89454d968adf9e75cf10de
Source dataset
uspto-grants-1989_06
Patent number
US04840963

Reaction notes

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