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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 404274Generated: October 25, 2026

Methyl Ethyl Ketone → 5-Bromo-2,3-dimethyl-1H-indole

https://huagongshe.com/reaction/404274

Reaction equation

Participants

RoleNameHCIDCharge
ReactantMethyl Ethyl KetoneHCID 6569—
Reactant4-Bromophenylhydrazine hydrochlorideHCID 12157—
SolventEthanolHCID 702—
Product5-Bromo-2,3-dimethyl-1H-indoleHCID 1279309767%

Reaction Steps

Following a published procedure (Gundersen, E. G. U.S. Patent App. Publ. US 2005/070592) 2-Butanone (0.11 mL, 1.278 mmol) was added to a solution of 4-bromophenylhydrazine hydrochloride (0.300 g, 1.342 mmol in EtOH (3.8 mL). The mixture was heated to reflux for 22 h, concentrated in vacuo, and partitioned between EtOAc and 1N HCl. The organic layer was washed with H2O and saturated aqueous NaHCO3, dried over Na2SO4, filtered, and concentrated. The crude residue was purified by chromatography (SiO2, 0-20% EtOAc/Hexane) to afford the desired indole as a pink powder (200 mg, 67%).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS08748473B2
Source datasetuspto-grants-2014_06
ORD IDord-a77b45717ef348488aa1730458407939
Source noteuspto-grants-2014_06