Piperazine → 1-(5-Chloropyridin-2-yl)piperazine

Temperature

110 °C

To a solution of 2,5-dichloropyridine (2 g) in dimethylformamide (30 mL) was added potassium carbonate (3.73 g) and piperazine (1.16 g) and the mixture was stirred at 110° C. for 4 hours. After cooling the reaction mixture, thereto was added ethyl acetate and an aqueous saturated sodium hydrogencarbonate solution and the mixture was extracted with ethyl acetate. The organic layer was washed with water, dried over magnesium sulfate and filtered. The filtrate was concentrated in vacuo and the resultant crude product was purified by column chromatography on NH-silica gel (Chromatorex NH-silica gel, solvent: chloroform/methanol=100/0 to 99/1) to obtain 5-chloro-2-(1-piperazinyl)pyridine (0.28 g, Yield: 10%) as a pale yellow solid.

1. temperatureAfter cooling the reaction mixture
2. extractionan aqueous saturated sodium hydrogencarbonate solution and the mixture was extracted with ethyl acetate
3. washThe organic layer was washed with water
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. concentrationThe filtrate was concentrated in vacuo
7. customthe resultant crude product was purified by column chromatography on NH-silica gel (Chromatorex NH-silica gel, solvent: chloroform/methanol=100/0 to 99/1)

ORD record

ord-8a7a5ce49bf646938a9726503156bb7d

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07872006B2