反应详情

To a solution of (2S)-2-ethoxycarbonylpiperazine-1-carboxylic acid 1-tert-butyl ester D-tartarate (9.56 g) in tetrahydrofuran (90 ml) and water (90 ml) was added sodium bicarbonate (7.87 g) under ice-cooling. Benzyl chloroformate (4.01 ml) was added dropwise to the solution over 2 minutes at the same temperature, and stirred at room temperature for 15 minutes. Ethyl acetate (60 ml) and sodium chloride (5 g) was added to the mixture. The organic layer was washed with brine, dried over magnesium sulfate, and evaporated under reduced pressure to give (2S)-2-ethoxycarbonylpiperazine-1,4-dicarboxylic acid 4-benzyl ester 1-tert-butyl ester (10.4 g) as a colorless oil.

1. temperaturecooling
2. washThe organic layer was washed with brine
3. dry with materialdried over magnesium sulfate
4. customevaporated under reduced pressure