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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 549073Generated: October 30, 2026

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

https://huagongshe.com/reaction/549073

Reaction equation

Participants

RoleNameHCIDCharge
ReactantPhosphorus oxychlorideHCID 24813—
Reactant7-aza-1H-indole N-oxideHCID 21959097—
Product4-Chloro-1H-pyrrolo[2,3-b]pyridineHCID 11389493—

Reaction Steps

1H-Pyrrolo[2,3-b]pyridine-N-oxide (10.0 g, Reference Example 65) in phosphorous oxychloride (75 mL) was heated at reflux for 8 hours. The excess phosphorous oxychloride was evaporated and the residue was taken up in water and the solution was brought to a pH=8-9, the resultant precipitate was filtered and air-dried to give the title compound as an off-white solid (10.2 g). MS: 152 (MH+). 1H NMR (CDCl3): δ 8.2 (d, 1H), 7.5 (d, 1H), 7.2 (d, 2H), 6.6 (d, 2H).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS07943616B2
Source datasetuspto-grants-2011_05
ORD IDord-ca88ad62ac5a4f81b3b57b7a9a549bbf
Source noteuspto-grants-2011_05