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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1752562Generated: October 28, 2026

Acetic Anhydride → 1-(5-Bromo-1H-indazol-1-yl)ethanone

https://huagongshe.com/reaction/1752562

Reaction equation

Participants

RoleNameHCIDCharge
ReactantAcetic AnhydrideHCID 7918—
ReactantIsoamyl NitriteHCID 8053—
Reactant4-Bromo-2-methylanilineHCID 11423—
ReactantSodium BicarbonateHCID 516892—
ReactantPotassium AcetateHCID 517044—
SolventChloroformHCID 6212—
Product1-(5-Bromo-1H-indazol-1-yl)ethanoneHCID 15278610—

Reaction Conditions

Temperature5 °C

Reaction Steps

4-Bromo-2-methylaniline (25.0 g, 134 mmol) was dissolved in chloroform (250 mL), and the mixture was cooled to 5° C. Acetic anhydride (35 mL, 343 mmol) was added dropwise, and the mixture was allowed to warm to ambient temperature. Potassium acetate (3.97 g, 40.4 mmol) and isoamylnitrite (35 mL, 262 mmol) were added, and the mixture was heated at 70° C. overnight. The mixture was neutralized with saturated sodium bicarbonate and extracted with methylene chloride. The combined organic layers were concentrated under reduced pressure, and the resulting residue was triturated with methanol to afford the title compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 8.45 (s, 1H) 8.26 (d, J=8.82 Hz, 1H) 8.17 (d, J=1.70 Hz, 1H) 7.77 (dd, J=8.82, 2.03 Hz, 1H) 2.72 (s, 3H).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS09163007B2
Source datasetuspto-grants-2015_10
ORD IDord-0a38bdaa9a3d46f6a17f89ea6cbf96b9
Source noteuspto-grants-2015_10