反应详情

温度

-10 °C

32 g (0.1 mol) of N-benzyloxycarbonyl-L-alanyl-L-proline were dissolved in 300 ml of dry tetrahydrofuran and the solution was cooled to -10° C. 12.7 ml (0.1 mol) of N-ethylmorpholine and 13.1 ml (0.1 mol) of isobutyl chloroformate were added and the solution was stirred for 20 minutes while maintaining the temperature at -10° C. 9.3 ml of aniline were then added and the mixture was stirred at 0° C. for 1 hour. The mixture was found to be slightly acidic and a further 1 g of N-ethylmorpholine was added. The solution was then left to stand at room temperature for 16 hours. The solution was evaporated, there being obtained a white crystalline solid which was treated with 500 ml of ether, filtered, washed and dried to give 31.8 g of N-benzyloxycarbonyl-L-alanyl-L-proline anilide of melting point 139.5°-140.5° C.; [α]D20 =-125.5° (c=1.195% in methanol). A second crop (1.4 g; melting point 138°-139° C.) was obtained by evaporating the mother liquor to a small volume, when crystallisation took place. The total yield was 81%.

1. temperaturewhile maintaining the temperature at -10° C
2. stirringthe mixture was stirred at 0° C. for 1 hour
3. waitThe solution was then left
4. waitto stand at room temperature for 16 hours
5. customThe solution was evaporated
6. customthere being obtained a white crystalline solid which
7. filtrationfiltered
8. washwashed
9. customdried