反应详情

温度

-5 °C

7.5 g (0.034 mol) of N-benzyloxycarbonyl-L-alanine were dissolved in 50 ml of dry tetrahydrofuran and the solution was cooled to -5° C. 4.26 ml (0.034 mol) of N-ethylmorpholine and 4.14 ml (0.034 mol) of pivaloyl chloride were then added and the solution was stirred at -5° C. for 30 minutes. To this mixture was then added a solution of 7.0 g (0.034 mol) of L-alanine ethylamide hydrobromide in 50 ml of dimethylformamide followed by 8.5 ml (0.068 mol) of N-ethylmorpholine. The solution was stirred at -10° C. for 1 hour and then left to stand for 16 hours at room temperature. The solvents were removed by evaporation; the product crystallising on the addition of water. The yield of N-benzyloxycarbonyl-L-alanyl-L-alanine obtained was 9.05 g (83%); melting point 203°-205° C.; [α]D20 =-1.1° (c=1.02% in dimethylformamide; [α] 36520 =-9.2° (c=1.02% in dimethylformamide).

1. stirringThe solution was stirred at -10° C. for 1 hour
2. waitleft
3. waitto stand for 16 hours at room temperature
4. customThe solvents were removed by evaporation
5. customthe product crystallising on the addition of water