反应详情

(2)In 970 ml of acetonitrile was dissolved 175 g (0.968 mol) of p-methoxybenzyloxyacetaldehyde (2d), followed by addition of 150 g (0.968 mol)of 2,2-dichloro-3-methylbutyraldehyde (1). Then, 1300 ml of 28% aqueous ammonia was further added dropwise under ice-cooling. After completion of dropwise addition, the mixture was allowed to stand at room temperature for 4 days. This reaction mixture was concentrated under reduced pressure and extracted with methylene chloride. The organic layer was washed with saturated brine and dried over MgSO4 and the solvent was distilled off under reduced pressure. The crude product was dissolved in ethyl acetate. To this solution was added a solution of oxalic acid (89.8 g, 0.968 mol)in ethyl acetate (70 ml)and the resulting oxalate was collected by filtration and rinsed with ethyl acetate. This oxalate was neutralized with 2N-sodium hydroxide and extracted with ethyl acetate. The organic layer was washed with water and dried over magnisium sulfate. The solvent was then distilled off under reduced pressure to provide 165 g (yield 69%)of 4-isopropyl-2-(p-methoxybenzyloxymethyl)-1H-imidazole (3d)as oil.

1. temperaturecooling
2. additionAfter completion of dropwise addition
3. concentrationThis reaction mixture was concentrated under reduced pressure
4. extractionextracted with methylene chloride
5. washThe organic layer was washed with saturated brine
6. dry with materialdried over MgSO4
7. distillationthe solvent was distilled off under reduced pressure
8. dissolutionThe crude product was dissolved in ethyl acetate
9. filtrationthe resulting oxalate was collected by filtration
10. washrinsed with ethyl acetate
11. extractionextracted with ethyl acetate
12. washThe organic layer was washed with water
13. dry with materialdried over magnisium sulfate
14. distillationThe solvent was then distilled off under reduced pressure