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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 324363Generated: October 25, 2026

Hydrochloric Acid → 5-chloro-3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole

https://huagongshe.com/reaction/324363

Reaction equation

Participants

RoleNameHCIDCharge
ReactantHydrochloric AcidHCID 313—
ReactantPotassium HydroxideHCID 14797—
Reactant5-ChloroindoleHCID 87110—
ReactantPiperidin-4-one hydrateHCID 21584170—
SolventEthanolHCID 702—
Product5-chloro-3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indoleHCID 3050532—

Reaction Steps

A mixture of 5-chloro-1H-indole (25 g), piperidin-4-one, hydrate, hydrochloride (71 g), and potassium hydroxide (38 g) in ethanol (450 ml) was refluxed for 6 hours. After cooling inorganic salts were filtered off and ethanol evaporated in vacuo. To the remaining oil was added brine (500 ml) and ethyl acetate (2×200 ml). The organic phase was separated and worked-up as above. Yield of crude title product: 45 g (semicrystalline).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS06218394B1
Source datasetuspto-grants-2001_04
ORD IDord-9d217abfacd344f19a447153eab2e03c
Source noteuspto-grants-2001_04