Phosphorus oxychloride → 5-Chloro-1H-pyrrolo(3,2-b)pyridine

HRID 651650Notes

Reaction equation

HRID 651650 reaction equation
[N:1]1[CH:2]=[CH:3][C:4]2[C:9]=1[CH:8]=[CH:7][C:6](=O)[N:5]=2.P(Cl)(Cl)([Cl:13])=O>>[Cl:13][C:6]1[N:5]=[C:4]2[CH:3]=[CH:2][NH:1][C:9]2=[CH:8][CH:7]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 181764495H-Pyrrolo[3,2-b]pyridin-5-one

Product 1

HCID 123842375-Chloro-1H-pyrrolo(3,2-b)pyridine

Procedure

A mixture of pyrrolo[3,2-b]pyrid-5-one (prepared according to the procedure described in J. Med. Chem. 1990, 33, 2087) (1.33 g, 9.91 mmol) and 20 mL of phosphorous oxychloride is heated in a sealed Parr high pressure stainless steel vessel at 180° C. for 2.5 hours. After cooling, excess phosphorous oxychloride is removed in vacuo. The residue is cooled in an ice bath and quenched with ice water. The resulting mixture is neutralized by addition of saturated NaHCO3 solution and extracted with EtOAc (3×). The combined organic layers are dried over MgSO4, filtered and concentrated in vacuo. The crude product (1.07 g, 7.01 mmol) is used in the subsequent step without further purification.

Workup

  1. customprepared
  2. temperatureAfter cooling
  3. customexcess phosphorous oxychloride is removed in vacuo
  4. temperatureThe residue is cooled in an ice bath
  5. customquenched with ice water
  6. additionThe resulting mixture is neutralized by addition of saturated NaHCO3 solution
  7. extractionextracted with EtOAc (3×)
  8. dry with materialThe combined organic layers are dried over MgSO4
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-95cd96aa7b094e93a2ec8b0dbb5eb4c8
Source dataset
uspto-grants-2001_08
Patent number
US06281227B1

Reaction notes

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