反应详情

温度

-10 °C

32 g of BOC-Asn-Leu-Ser-Thr-OBzl are dissolved in 192 ml of 90% strength trifluoroacetic acid and the solution left for 45 minutes at 20° C. Thereafter the solution is concentrated to about 40ml, mixed with 400 ml of ether whilst stirring and stirred for about 20 minutes at 35° C. under reflux. The crystal suspension is then cooled to -10° C. and is left to stand overnight at -10° C. The precipitate is filtered off, washed three times with ether and dried in vacuo over sodium hydroxide. Melting point 125°- 127° C.; Rf4 = 0.33 (on silica gel).

1. concentrationThereafter the solution is concentrated to about 40ml
2. additionmixed with 400 ml of ether
3. stirringstirred for about 20 minutes at 35° C.
4. temperatureunder reflux
5. waitis left
6. waitto stand overnight at -10° C
7. filtrationThe precipitate is filtered off
8. washwashed three times with ether
9. dry with materialdried in vacuo over sodium hydroxide