Phosphorus oxychloride → 4-Chloro-1H-pyrrolo[2,3-b]pyridine

HRID 397372Notes

Reaction equation

HRID 397372 reaction equation
[NH:1]1[C:5]2=[N+:6]([O-])[CH:7]=[CH:8][CH:9]=[C:4]2[CH:3]=[CH:2]1.P(Cl)(Cl)([Cl:13])=O>>[Cl:13][C:9]1[CH:8]=[CH:7][N:6]=[C:5]2[NH:1][CH:2]=[CH:3][C:4]=12

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178526243HCID 178526243, compound

Product 1

HCID 113894934-Chloro-1H-pyrrolo[2,3-b]pyridineYield 42%

Procedure

1H-Pyrrolo[2,3-b]pyridine 7-oxide (1.86 g, 13.9 mmol, literature reference: J. Org. Chem. 45(20):4045-8 (1980)) was dissolved in 10 mL of phosphorus oxychloride. The reaction mixture was refluxed for 6 hours, cooled to room temperature and concentrated. The residue was extracted with ethyl acetate/water. The organic layer was washed with brine to pH 6, dried over anhydrous sodium sulfate, concentrated and dried in a vacuum oven overnight to give 0.88 g (42%) of 4-chloro-1H-pyrrolo[2,3-b]pyridine as a tan solid. 1H NMR (360 MHz, DMSO-d6) δ 11.99 (s, br, 1H, NH), 8.16 (d, J=5.15 Hz, 1H), 7.57 (t, br, J=3.38 Hz, 1H), 7.17 (d, J=5.15 Hz, 1H), 6.49 (dd, J=1.80, 3.38 Hz, 1H). MS m/e 153 [M+].

Workup

  1. temperatureThe reaction mixture was refluxed for 6 hours
  2. concentrationconcentrated
  3. extractionThe residue was extracted with ethyl acetate/water
  4. washThe organic layer was washed with brine to pH 6
  5. dry with materialdried over anhydrous sodium sulfate
  6. concentrationconcentrated
  7. customdried in a vacuum oven overnight

Sources & evidence

ORD record
ord-775488dc6a04451db03385e03b5e9747
Source dataset
uspto-grants-2003_08
Patent number
US06610688B2

Reaction notes

Loading…