反应详情

To a solution of (S)-2-(((benzyloxy)carbonyl)amino)butanoic acid (10.0 g, 42.1 mmol) in methanol (100 mL) and toluene (300 mL) was added dropwise at room temperature under argon trimethylsilyldiazomethane (23.2 mL, 46.4 mmol). After stirring at room temperature for 1 hour, the reaction mixture was concentrated and the residue was extracted with a solution of EtOAc and brine. The combined organic layers were dried over Na2SO4, filtered and the filtrate was concentrated. The residue was purified by column chromatography (120 g SiO2) using EtOAc in hexane from 0% to 30% in order to give the title compound (5.2 g, 48%) as a colorless oil. LC-MS: [M+H] 252.1; Rt 0.93 min; (LCMS method 1).

1. concentrationthe reaction mixture was concentrated
2. extractionthe residue was extracted with a solution of EtOAc and brine
3. dry with materialThe combined organic layers were dried over Na2SO4
4. filtrationfiltered
5. concentrationthe filtrate was concentrated
6. customThe residue was purified by column chromatography (120 g SiO2)