反应详情

To 4.78 g (0.037 moles) of 3-oximino-2,4-pentanedione dissolved in 40 ml of acetonitrile was added 3.82 g (0.037 moles) of 2-aminobutyric acid. The mixture was brought to reflux, while stirring rapidly under nitrogen, with an oil bath. After 22.5 h the reaction mixture was cooled, suction filtered, and the residue washed with acetonitrile (50 ml). The combined filtrates were concentrated in vacuo, and the resulting oil dissolved in 1 M hydrochloric acid (30 ml). The acid solution was washed with methylene chloride (4×20 ml), then neutralized with solid potassium carbonate. Extraction with methylene chloride, followed by drying over anhydrous potassium carbonate and concentration in vacuo furnished 0.021 moles (67.8%) yield based on recovered d,l-norvaline) of 5-acetyl-2-ethyl-4-methylimidazole.

1. temperatureto reflux
2. temperatureAfter 22.5 h the reaction mixture was cooled
3. filtrationsuction filtered
4. washthe residue washed with acetonitrile (50 ml)
5. concentrationThe combined filtrates were concentrated in vacuo
6. dissolutionthe resulting oil dissolved in 1 M hydrochloric acid (30 ml)
7. washThe acid solution was washed with methylene chloride (4×20 ml)
8. extractionExtraction with methylene chloride
9. dry with materialby drying over anhydrous potassium carbonate and concentration in vacuo
10. customfurnished 0.021 moles (67.8%)
11. customyield
12. customon recovered d,l-norvaline) of 5-acetyl-2-ethyl-4-methylimidazole