Phosphorus oxychloride → 4-Chloro-5-fluoro-1H-pyrrolo(2,3-b)pyridine

HRID 490501Notes

Reaction equation

HRID 490501 reaction equation
[F:1][C:2]1[CH:3]=[C:4]2[CH:11]=[CH:10][NH:9][C:5]2=[N+:6]([O-])[CH:7]=1.C(=O)([O-])O.[Na+].P(Cl)(Cl)([Cl:19])=O>>[Cl:19][C:3]1[C:2]([F:1])=[CH:7][N:6]=[C:5]2[NH:9][CH:10]=[CH:11][C:4]=12

Participants

4

Reactant 3

HCID 24813Phosphorus oxychloride2×HCID 516892Sodium BicarbonateHCID 178526273HCID 178526273, compound

Product 1

HCID 497616114-Chloro-5-fluoro-1H-pyrrolo(2,3-b)pyridine

Procedure

A solution of 1.7 g of 5-fluoro-1H-pyrrolo[2,3-b]pyridine-7-oxide in 10 cm3 of phosphorus oxychloride is maintained at the reflux point of the POCl3 for 8 hours. After distilling off the POCl3 under vacuum, the residue is treated with 50 g of ice, and the pH of the solution obtained is brought in the region of 8-9 by addition of sodium hydrogen carbonate. The aqueous phase is extracted with five times 80 cm3 of ethyl acetate. The combined organic phases are then dried over magnesium sulfate, filtered and concentrated to dryness under reduced pressure (13 kPa). 1.3 g of 4-chloro-5-fluoro-1H-pyrrolo[2,3-b]pyridine are thus obtained in the form of a solid, the characteristics of which are as follows:

Workup

  1. distillationAfter distilling off the POCl3 under vacuum
  2. additionthe residue is treated with 50 g of ice
  3. customthe pH of the solution obtained
  4. extractionThe aqueous phase is extracted with five times 80 cm3 of ethyl acetate
  5. dry with materialThe combined organic phases are then dried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated to dryness under reduced pressure (13 kPa)

Sources & evidence

ORD record
ord-69c2748e18fb479191767bfddc281475
Source dataset
uspto-grants-2009_05
Patent number
US07528147B2

Reaction notes

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