反应详情

To a solution of Boc-D-leucine monohydrate (2.0 g, 8.0 mmol), triethylamine (5.6 mL, 40.1 mmol), and dimethylamine hydrochloride (1.31 g, 16.0 mmol) in DMF (15 mL) at room temperature was added PyBOP (4.59 g, 8.82 mmol). The reaction mixture was stirred overnight then diluted with EtOAc (50 mL) and washed with water (4×50 mL). The combined organic extracts were dried (Na2SO4) and evaporated under vacuum. The crude residue was purified by SiO2 chromatography (80 g, hexanes/EtOAc, 1:1) to give 1.19 g (58%) of ((R)-1-dimethylcarbamoyl-3-methyl-butyl)-carbamic acid tert-butyl ester as a colorless viscous oil.

1. washwashed with water (4×50 mL)
2. dry with materialThe combined organic extracts were dried (Na2SO4)
3. customevaporated under vacuum
4. customThe crude residue was purified by SiO2 chromatography (80 g, hexanes/EtOAc, 1:1)