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

Temperature

90 °C

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.

1. temperatureto cool to room temperature
2. customThe product crystallized
3. customwas isolated by filtration
4. temperaturethe solution was heated
5. temperatureat reflux for 3 hours
6. concentrationThe solution was then concentrated in vacuo
7. customto give a residue that
8. customwas partitioned between ether and water
9. customThe phases were separated
10. extractionThe aqueous phase was then extracted twice with ethyl acetate
11. washThe combined ethyl acetate phases were washed once with brine
12. dry with materialdried over Na2SO4
13. filtrationfiltered
14. customThe product was isolated via filtration

ORD record

ord-67b2e059594e4ce386ee2274c376b35c

Source dataset

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07449576B1