反应详情

Crude ethyl (2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylate (7.82 g) synthesized according to the process (acid chloride method) similar to that described in Patent reference 1 was dissolved in ethanol (24 mL). While the solution was cooled with ice and stirred, 1 mol/L aqueous solution of sodium hydroxide (23.55 mL) was dropped. After the solution was stirred for 1.5 hours while the temperature was kept, the solvent was distilled off under reduced pressure. Water (39 mL) was added to the residue, and the obtained solution was washed with two portions of ethyl acetate (39 mL), and then water was distilled off under reduced pressure. Acetone (157 mL) was added to the residue, and the solution was stirred overnight at room temperature. The precipitated crystalline product was collected by filtration, washed with a mixture of 3% water-acetone (30 mL), washed again with acetone (30 mL), and dried in air to obtain white solid sodium (2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylate (5.36 g, 69.9%). The NMR data of the solid product were the same as those in Example 9.

1. temperatureWhile the solution was cooled with ice
2. stirringAfter the solution was stirred for 1.5 hours while the temperature
3. distillationthe solvent was distilled off under reduced pressure
4. additionWater (39 mL) was added to the residue
5. washthe obtained solution was washed with two portions of ethyl acetate (39 mL)
6. distillationwater was distilled off under reduced pressure
7. additionAcetone (157 mL) was added to the residue
8. stirringthe solution was stirred overnight at room temperature
9. filtrationThe precipitated crystalline product was collected by filtration
10. washwashed with a mixture of 3% water-acetone (30 mL)
11. washwashed again with acetone (30 mL)
12. customdried in air