反应详情

42.4 g of ethyl 4-methyl-3-oxopentanoate are dissolved in 100 ml of glacial acetic acid, and 21 g of sodium nitrite, dissolved in 100 ml of water, are added at 5° C. Over a period of one hour, the mixture is allowed to warm to room temperature, 100 ml of water are added and the mixture is stirred at room temperature for another hour. The mixture is extracted three times with in each case 150 ml of methyl tert-butyl ether, 200 ml of water are added to the combined organic phases and the mixture is neutralized by addition of solid NaHCO3. The organic phase is removed, washed with saturated NaCl solution and dried over MgSO4, and the solvent is removed under reduced pressure. This gives 46 g of ethyl 2-hydroxyimino-4-methyl-3-oxopentanoate as an oil. C8H13NO4 (187.20), MS (ESI)=188 (M+H+).

1. additionare added at 5° C
2. extractionThe mixture is extracted three times with in each case 150 ml of methyl tert-butyl ether, 200 ml of water
3. additionare added to the combined organic phases
4. additionthe mixture is neutralized by addition of solid NaHCO3
5. customThe organic phase is removed
6. washwashed with saturated NaCl solution
7. dry with materialdried over MgSO4
8. customthe solvent is removed under reduced pressure