Water → Ethyl 6-(piperazin-1-yl)nicotinate

Temperature

80 °C

Ethyl 6-chloronicotinate (1.12 g) was dissolved in DMF (30 mL), and 1-tert-butoxycarbonylpiperazine (1.24 g) and potassium carbonate (1.00 g) were added thereto. The mixture was stirred at 80° C. for 18 hr. Water (100 mL) was added to the reaction mixture and the mixture was extracted with ethyl acetate. The extract was washed successively with saturated aqueous sodium hydrogencarbonate solution and brine and dried. The solvent was evaporated under reduced pressure. The residue was dissolved in dichloromethane (10 mL), and trifluoroacetic acid (5 mL) was added thereto at room temperature. The mixture was stirred for 2 hr and the reaction mixture was concentrated under reduced pressure. Water (50 mL) was added to the residue, and the mixture was washed with diethyl ether. The aqueous layer was basified with aqueous sodium hydrogen carbonate solution. The mixture was extracted with chloroform. The extract was dried and the mixture was concentrated under reduced pressure to give 1-(5-ethoxycarbonyl-2-pyridyl)piperazine (1.17 g) as an oil.

1. extractionthe mixture was extracted with ethyl acetate
2. washThe extract was washed successively with saturated aqueous sodium hydrogencarbonate solution and brine
3. customdried
4. customThe solvent was evaporated under reduced pressure
5. dissolutionThe residue was dissolved in dichloromethane (10 mL)
6. additiontrifluoroacetic acid (5 mL) was added
7. customat room temperature
8. stirringThe mixture was stirred for 2 hr
9. concentrationthe reaction mixture was concentrated under reduced pressure
10. additionWater (50 mL) was added to the residue
11. washthe mixture was washed with diethyl ether
12. extractionThe mixture was extracted with chloroform
13. customThe extract was dried
14. concentrationthe mixture was concentrated under reduced pressure

ORD record

ord-794febebe4af4b26b5ee6d7afe56f0e1

Source dataset

uspto-grants-2006_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07060722B2