Citric Acid → (2S,3S)-1,2-Epoxy-3-(Cbz-amino)-4-phenylbutane

Temperature

10 °C

25.5 g of the crude N-benzyloxycarbonyl-3(S)-amino-2(R)-p-toluenesulfonyl-4-phenyl-1-butanol obtained in the above Example 1 was dissolved in 750 ml of methanol. Then 13.9 g of potassium carbonate was added thereto at 10° C. and the resulting mixture was stirred for 3 hours at 10° to 20° C. The pH value of the reaction mixture was adjusted to 7 to 7.5 by adding a 5% aqueous solution of citric acid. After distilling off the solvent under reduced pressure, 150 ml of water was added to the concentrate. Then it was extracted with 150 ml portions of ethyl acetate twice and the extract was washed with 50 ml of a saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. After filtering off the sodium sulfate and distilling off the solvent under reduced pressure, 14.4 g of crude N-benzyloxycarbonyl-3(S)-amino-1,2(S)-epoxy-4-phenylbutane was obtained.

1. distillationAfter distilling off the solvent under reduced pressure, 150 ml of water
2. additionwas added to the concentrate
3. extractionThen it was extracted with 150 ml portions of ethyl acetate twice
4. washthe extract was washed with 50 ml of a saturated aqueous solution of sodium chloride
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationAfter filtering off the sodium sulfate
7. distillationdistilling off the solvent under reduced pressure

ORD record

ord-b212bf781c9544b78539304b8e1f0422

Source dataset

uspto-grants-1996_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05488118