反応 #84040
ord-39ad65ac9fc142649a7bb14dd4f1e092
反応方程式
反応条件
後処理
- 1その他reach room temperature
- 2その他The reaction mixture is separated with ether (3×50 mL)
- 3その他the aqueous layer is contained in a round bottom flask
- 4温度cooled over an ice-water bath
- 5workup.ADDITIONConcentrated HCl (aq) is added drop wise until pH 2
- 6その他is brought to room temperature
- 7抽出extracted with 2-Me-THF (3×50 mL)
- 8乾燥dried (MgSO4)
- 9その他the solids removed by filtration
- 10その他the solvents of the filtrate removed under reduced pressure
- 11その他The compound was purified by silicagel chromatography with gradient elution from CH2Cl2 to CH2Cl2/MeOH/acetic acid 17/2/1
- 12workup.ADDITIONFractions containing product
- 13その他the solvent were removed in vacuum
- 14その他resulting in N-methoxycarbonyl-L-leucine (1.9 g, 32%)
実験手順
An aqueous NaOH (1M, 2.6 mL) solution is added, while stirring, to L-Leucine (4 g, 30.5 mmol) in a round bottom flask (250 mL). To this solution was added sodium carbonate (1.62 g, 15.2 mmol). The flask is cooled to 0° C. in an ice-water bath. Methyl chloroformate (2.6 mL, 33.5 mmol) is added drop wise and the reaction mixture is allowed to stir for 15 hours and reach room temperature. The reaction mixture is separated with ether (3×50 mL), and the aqueous layer is contained in a round bottom flask and cooled over an ice-water bath. Concentrated HCl (aq) is added drop wise until pH 2. The reaction mixture is brought to room temperature and extracted with 2-Me-THF (3×50 mL). The organic layers are pooled, dried (MgSO4), the solids removed by filtration, and the solvents of the filtrate removed under reduced pressure. The compound was purified by silicagel chromatography with gradient elution from CH2Cl2 to CH2Cl2/MeOH/acetic acid 17/2/1. Fractions containing product were combined and the solvent were removed in vacuum, resulting in N-methoxycarbonyl-L-leucine (1.9 g, 32%).