反应详情

温度

70 °C

5.8 g of 2-(1-methylethyl)-4-imidazolidinone hydrochloride ((5); R4 =H, R5 =isopropyl) (0.035 moles) are shaken in 10 ml water and treated with 2.4 g potassium carbonate (0.0174 moles). 4.5 g ethyl 3,4-epoxybutanoate and 6 ml acetone are added, and stirring is maintained for 45 h at 70° C. After evaporation, the residue is chromatographed on silica, eluting with 8:2 ethyl acetate/methanol. The main fractions are collected and evaporated. The oil that remains is taken up with ethyl acetate. After being left to stand overnight the white compound obtained is filtered: 1.3 g ethyl 2-(1-methylethyl)-4-oxo-1-imidazolidine-β-hydroxybutanoate m.p. 118°-122° C. 0.95 g of this compound (3.7 mmoles) are heated to boiling for 15 h in 4 ml DMF and 1 ml water. After evaporation in vacuo, the residue is taken up with methanol, and the solution is filtered. 0.37 g oxiracetam is obtained as a white crystalline powder, m.p. 167°-70° C. (63.2%).

1. customAfter evaporation
2. customthe residue is chromatographed on silica
3. washeluting with 8:2 ethyl acetate/methanol
4. customThe main fractions are collected
5. customevaporated
6. waitAfter being left
7. customthe white compound obtained
8. filtrationis filtered
9. customAfter evaporation in vacuo
10. filtrationthe solution is filtered