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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 270768Generated: October 30, 2026

Hydrogen Bromide → 1-(5-Methoxy-2-methylphenyl)piperazine

https://huagongshe.com/reaction/270768

Reaction equation

Participants

RoleNameHCIDCharge
ReactantHydrogen BromideHCID 260—
ReactantAnisoleHCID 7519—
ReactantTriethylamineHCID 8471—
Reactant3-[2-(5-Methoxy-2-methyl-phenylamino)-ethyl]-oxazolidin-2-oneHCID 21071128—
SolventAcetic AcidHCID 176—
SolventEthanolHCID 702—
SolventDichloromethaneHCID 6344—
Product1-(5-Methoxy-2-methylphenyl)piperazineHCID 19357208—

Reaction Conditions

Temperature90 °C

Reaction Steps

To 505 mg (2.0 mmol) of 3-[2-(5-Methoxy-2-methyl-phenylamino)-ethyl]-oxazolidin-2-one in a flask was added 2 mL of 48% HBr in acetic acid, 1 mL of acetic acid, and 1 mL of anisole, and the mixture was heated at 90° C. for six hours. The solution was allowed to cool to room temperature, and 5 mL of CH2Cl2 was added. The product crystallized and was isolated by filtration. The solids were dissolved in 55 mL of ethanol, 201 mg (2 mmol) of triethylamine were added, and the solution was heated at reflux for 3 hours. The solution was then concentrated in vacuo to give a residue that was partitioned between ether and water. The phases were separated, and the aqueous phase as basified with 1M NaOH. The aqueous phase was then extracted twice with ethyl acetate. The combined ethyl acetate phases were washed once with brine, dried over Na2SO4, filtered, and acidified with 2M HCl in ether. The product was isolated via filtration.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS07449576B1
Source datasetuspto-grants-2008_11
ORD IDord-67b2e059594e4ce386ee2274c376b35c
Source noteuspto-grants-2008_11