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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 24368Generated: October 26, 2026

Hydrochloric Acid → 5-Methylindolin-2-one

https://huagongshe.com/reaction/24368

Reaction equation

Participants

RoleNameHCIDCharge
ReactantHydrochloric AcidHCID 313—
Reactant5-MethylisatinHCID 11840—
ReactantHydrazine hydrate (1:1)HCID 24654—
Product5-Methylindolin-2-oneHCID 532571647.5%

Reaction Conditions

Temperature150 °C

Reaction Steps

A mixture of 5-methylisatin (15.0 g) and 60 ml of hydrazine hydrate was stirred at 140-160° C. for 4 hours. The reaction mixture was cooled to room temperature, poured into 300 ml of ice water and acidified to pH 2 with 6 N hydrochloric acid. After standing at room temperature for 2 days, a precipitate formed which was collected by vacuum filtration, washed with water and dried under vacuum to give 6.5 g (47% yield) of 5-methyl-2-oxindole.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS06855730B2
Source datasetuspto-grants-2005_02
ORD IDord-a4e1f14131e349d8b033754a9d3dbffd
Source noteuspto-grants-2005_02