反应详情

A mixture of 8.5 g (0.05 mole) of 1-benzyl-2-methylimidazole monohydrate, 50 ml of 36% formaldehyde, 6 ml of acetic acid and 8.0 g (0.098 mole) of sodium acetate is stirred and heated at reflux for 26 hours. It was then stirred over a weekend (about 65 hours) at room temperature and neutralized with solid sodium carbonate. The neutral solution was extracted with ethyl acetate, the extract dried (MgSO4) and evaporated under reduced pressure to an oil. Water (10 ml) and isopropanol (50 ml) were added to the oil, the solution stirred overnight then evaporated under reduced pressure. The oily residue obtained was taken up in water and the solution made strongly basic by addition of solid sodium hydroxide. It was chilled, layered with diethyl ether, and the white solid which formed removed by filtration and air dried. Yield=1.8 g (18%); m.p. 140°-146° C. It was purified by dissolution in 30 ml of hot (50° C.) ethyl acetate and filtration. Concentration of the filtrate to about two-thirds volume, and chilling, afforded 1.3 g of white solid; m.p. 147°-151° C. Thin layer chromatography in the system ethyl acetate:methanol:diethylamine (80:10:10) gave a single spot.

1. temperatureheated
2. temperatureat reflux for 26 hours
3. stirringIt was then stirred over a weekend (about 65 hours) at room temperature
4. extractionThe neutral solution was extracted with ethyl acetate
5. dry with materialthe extract dried (MgSO4)
6. customevaporated under reduced pressure to an oil
7. additionWater (10 ml) and isopropanol (50 ml) were added to the oil
8. stirringthe solution stirred overnight
9. customthen evaporated under reduced pressure
10. customThe oily residue obtained
11. temperatureIt was chilled
12. customthe white solid which formed
13. customremoved by filtration and air
14. customdried
15. filtrationIt was purified by dissolution in 30 ml of hot (50° C.) ethyl acetate and filtration
16. temperatureConcentration of the filtrate to about two-thirds volume, and chilling