反应详情

温度

0 °C

26.3 g of H-Asn-Leu-Ser-Thr-OBzl.TFA are dissolved in 100 ml of dimethylformamide, the solution is cooled to 0°C and successively mixed with 7.5 ml of triethylamine, 0.54 ml of glacial acetic acid and a solution of 14.4 g of BOC-Gly-ONP in 100 ml of dimethylformamide, stirred at room temperature until the mixture solidifies and left to stand for 2 days. Thereafter 300 ml of ethyl acetate are added whilst stirring and the mixture left to stand overnight at -10°C. The precipitate is filtered off, washed twice with ethyl acetate and twice with ether, stirred for half an hour with 200 ml of water, filtered off, washed with water and dried in vacuo. Melting point 227-228°C; [α]D = -23° (c = 2 in dimethylformamide); Rf9 = 0.50 (on silica gel).

1. waitleft
2. waitthe mixture left
3. waitto stand overnight at -10°C
4. filtrationThe precipitate is filtered off
5. washwashed twice with ethyl acetate and twice with ether
6. stirringstirred for half an hour with 200 ml of water
7. filtrationfiltered off
8. washwashed with water
9. customdried in vacuo