Isopropanol → HCID 86654826, compound

Temperature

60 °C

2-Methylimidazole was reacted with 1 equivalent of sodium hydride in 1,2-dimethoxyethane as a solvent at room temperature, and then 3 equivalents of 1-bromopropane was gradually added thereto, followed by stirring at 60° C. for 2 days. Approximately 1 day after start of stirring, an appropriate amount of 2-propanol was added thereto as a co-solvent. After completion of stirring, the solvent and unreacted 1-bromopropane were distilled off. The residual solid was recrystallized with acetone twice to obtain 1,3-di-n-propyl-2-methylimidazolium bromide as transparent and colorless crystals (No. 3 ionic liquid in Table 1). Next, the 1,3-di-n-propyl-2-methylimidazolium bromide was dissolved in water, and 1 equivalent of silver sulfate was added thereto, followed by stirring at room temperature for approximately 1 hour. The precipitate of resulting silver bromide was removed by filtration, and then water was distilled off. The residual solid was recrystallized with acetonitrile to obtain 1,3-di-n-propyl-2-methylimidazolium sulfate as white fine crystals. Subsequently, the 1,3-di-n-propyl-2-methylimidazolium sulfate was dissolved in water at 80° C., 1 equivalent of barium formate was added thereto, and the precipitate of resulting barium sulfate was removed by filtration. Water was removed from the aqueous solution of 1,3-di-n-propyl-2-methylimidazolium formate obtained as described above at 60° C. under reduced pressure to obtain desired 1,3-di-n-propyl-2-methylimidazolium formate as a colorless and highly viscous liquid.

1. stirringApproximately 1 day after start of stirring
2. stirringAfter completion of stirring
3. distillationthe solvent and unreacted 1-bromopropane were distilled off
4. customThe residual solid was recrystallized with acetone twice

ORD record

ord-56e62873e518466faceb573690125531

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08519013B2