2-Bromobutane → 1-Butyl-1-methylpyrrolidinium bromide

Temperature

65 °C

About 200 mL of acetonitrile (manufactured by Junsei Co., Ltd. in Japan) was mixed with about 523 mL (0.5 mol) of methylpyrrolidone (manufactured by Fluka Co., Ltd.) under a nitrogen atmosphere to form a liquid mixture. Subsequently, about 58.6 mL (0.55 mol) of 2-bromobutane (manufactured by Aldrich Co., Ltd.) was added into the liquid mixture drop by drop to form a mixed solution. Subsequently, the mixed solution was stirred at about 65° C. for about 48 hours under a nitrogen atmosphere, and was then stored at about 4° C. for about 12 hours to form crystals. After a supernatant was removed from the mixed solution, the crystals were dried at a temperature of about 35° C. and a pressure of about 0.2 atm for about 12 hours using a vacuum evaporator to remove a solvent therefrom. Subsequently, in order to remove impurities, the dried crystals were dissolved in about 100 mL of acetone, and were then stirred at a temperature of about 25° C. and a pressure of about 1 atm for about 30 minutes to form a solution. The solution was left at 4° C. for about 12 hours to form crystals again. After a supernatant was removed from the solution, the crystals were dried at a temperature of about 35° C. and a pressure of about 0.2 atm for about 12 hours using a vacuum evaporator. These processes were repeatedly conducted three times to obtain N-butyl-N-methylpyrrolidinium bromide at a yield of about 60%.

1. customto form a liquid mixture
2. customto form a mixed solution
3. waitwas then stored at about 4° C. for about 12 hours
4. customto form crystals
5. customAfter a supernatant was removed from the mixed solution
6. customthe crystals were dried at a temperature of about 35° C.
7. waita pressure of about 0.2 atm for about 12 hours using
8. customa vacuum evaporator
9. customto remove a solvent
10. customSubsequently, in order to remove impurities
11. dissolutionthe dried crystals were dissolved in about 100 mL of acetone
12. stirringwere then stirred at a temperature of about 25° C.
13. customa pressure of about 1 atm for about 30 minutes to form a solution
14. waitThe solution was left at 4° C. for about 12 hours
15. customto form crystals again
16. customAfter a supernatant was removed from the solution
17. customthe crystals were dried at a temperature of about 35° C.
18. waita pressure of about 0.2 atm for about 12 hours using
19. customa vacuum evaporator

ORD record

ord-6ae329c980d340f6943e379b253f82d1

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08961656B2