反应详情

To a stirred solution of (tert-butoxycarbonyl-methyl-amino)-acetic acid (37 g, 0.2 mol) and Et3N (60.6 g, 0.6 mol) in CH2Cl2 (300 mL) was added isobutyl chloroformate (27.3 g, 0.2 mmol) dropwise at −20° C. under argon. After stirring for 0.5 h, methylamino-acetic acid ethyl ester hydrochloride (30.5 g, 129 mmol) was added dropwise at −20° C. The mixture was allowed to warm to room temperature (c.a. 1 h) and quenched with water (500 mL). The organic layer was separated, washed with 10% citric acid solution, dried over Na2SO4, filtered and concentrated. The residue was purified by column chromatography (petroleum ether/EtOAc 1:1) to give {[2-(tert-butoxycarbonyl-methyl-amino)-acetyl]-methyl-amino}-acetic acid ethyl ester (12.5 g, 22

1. customquenched with water (500 mL)
2. customThe organic layer was separated
3. washwashed with 10% citric acid solution
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe residue was purified by column chromatography (petroleum ether/EtOAc 1:1)