反应详情

Crude ethyl (2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylate (15.29 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 stirred at room temperature, sodium carbonate (2.44 g) dissolved in water (24 mL) was dropped. After the solution was stirred at room temperature for 1 hour, it was further stirred at 90° C. to 95° C. for 2 hours. The solvent was distilled off under reduced pressure, and water (50 mL) was added to the residue. The obtained solution was washed with two portions of ethyl acetate (50 mL), and water was distilled off under reduced pressure. Acetone (400 mL) was dropped to the residue, and the obtained 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 (10.55 g, 70.3%). The NMR data of the solid product were the same as those in Example 9.

1. additionwas dropped
2. stirringAfter the solution was stirred at room temperature for 1 hour
3. stirringit was further stirred at 90° C. to 95° C. for 2 hours
4. distillationThe solvent was distilled off under reduced pressure, and water (50 mL)
5. additionwas added to the residue
6. washThe obtained solution was washed with two portions of ethyl acetate (50 mL), and water
7. distillationwas distilled off under reduced pressure
8. additionAcetone (400 mL) was dropped to the residue
9. stirringthe obtained solution was stirred overnight at room temperature
10. filtrationThe precipitated crystalline product was collected by filtration
11. washwashed with a mixture of 3% water-acetone (30 mL)
12. washwashed again with acetone (30 mL)
13. customdried in air