反应详情

A suspension of 2-tert-butoxycarbonylamino-3-(4-fluoro-phenylsulfanyl)-propionic acid methyl ester (2.28 g, 6.93 mmol) in methanol (10 ml) was vigorously stirred at room temperature during the addition of 2N aqueous sodium hydroxide solution (7 ml, 14 mmol). The resulting mixture was stirred at room temperature for 2 hours and then concentrated in vacuo. The residue was diluted with water (65 ml) and the aqueous layer was extracted with diethyl ether (2*50 ml). The aqueous layer was acidified with 1N hydrochloric acid and extracted with ethyl acetate. The organic phase was dried (anhydrous magnesium sulfate) and concentrated in vacuo to give, after purification by flash chromatography on silica gel, (dichloromethane/methanol: 98/2 to 96/4) 2-tert-butoxycarbonylamino-3-(4-fluoro-phenylsulfanyl)-propionic acid (2.06 g, 95%) as a pale yellow oil. Mass spectrum, 315 [M+H]+.

1. concentrationconcentrated in vacuo
2. additionThe residue was diluted with water (65 ml)
3. extractionthe aqueous layer was extracted with diethyl ether (2*50 ml)
4. extractionextracted with ethyl acetate
5. dry with materialThe organic phase was dried (anhydrous magnesium sulfate)
6. concentrationconcentrated in vacuo
7. customto give
8. customafter purification by flash chromatography on silica gel, (dichloromethane/methanol: 98/2 to 96/4) 2-tert-butoxycarbonylamino-3-(4-fluoro-phenylsulfanyl)-propionic acid (2.06 g, 95%) as a pale yellow oil