Hydrochloric Acid → 6-Chloro-1,3-dihydropyrrolo[3,2-B]pyridin-2-one

HRID 2394331Notes

Reaction equation

HRID 2394331 reaction equation
[NH2:1][C:2]1[C:3]([CH:9](C(OCC)=O)[C:10]([O:12]CC)=O)=[N:4][CH:5]=[C:6]([Cl:8])[CH:7]=1.Cl>>[Cl:8][C:6]1[CH:7]=[C:2]2[C:3]([CH2:9][C:10](=[O:12])[NH:1]2)=[N:4][CH:5]=1

Participants

3

Reactant 2

HCID 313Hydrochloric AcidHCID 106132393-Amino-2-bis(ethoxycarbonyl)methyl-5-chloropyridine

Product 1

HCID 104873236-Chloro-1,3-dihydropyrrolo[3,2-B]pyridin-2-one

Procedure

A mixture of 3-amino-2-bis(ethoxycarbonyl)methyl-5-chloropyridine and 6N HCl (325 mL) was heated at reflux for 4 hours. After removing the aqueous acid in vacuo, the residue was taken up in water and filtered to remove a small amount of black insoluble material. On adjustment of the filtrate to pH 6.5 with solid NaHCO3, 6-chloro-4-azaoxindole precipitated as a tan solid (2.6 g) which was collected by filtration. The filtrate was extracted with ethyl acetate and the combined extracts were dried (MgSO4) and concentrated to yield an additional quantity of 6-chloro-4-azaoxindole (3.6 g). The total yield was thus 6.2 g (71% overall from 2,5-dichloro-3-nitropyridine).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 4 hours
  3. customAfter removing the aqueous acid in vacuo
  4. filtrationfiltered
  5. customto remove a small amount of black insoluble material
  6. customOn adjustment of the filtrate to pH 6.5 with solid NaHCO3, 6-chloro-4-azaoxindole precipitated as a tan solid (2.6 g) which
  7. filtrationwas collected by filtration
  8. extractionThe filtrate was extracted with ethyl acetate
  9. dry with materialthe combined extracts were dried (MgSO4)
  10. concentrationconcentrated

Sources & evidence

ORD record
ord-be18176633a84d18974f14a021a9c25b
Source dataset
uspto-grants-1998_09
Patent number
US05811432

Reaction notes

Loading…