Trifluoroacetic acid → H-Ser-Thr-OBzl.TFA
Reaction equation
[NH:1](C(OC(C)(C)C)=O)[C@H:2]([C:5]([NH:7][C@H:8]([C:12]([O:14][CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)=[O:13])[C@@H:9]([CH3:11])[OH:10])=[O:6])[CH2:3][OH:4].[F:29][C:30]([F:35])([F:34])[C:31]([OH:33])=[O:32]>>[NH2:1][C@H:2]([C:5]([NH:7][C@H:8]([C:12]([O:14][CH2:15][C:16]1[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1)=[O:13])[C@@H:9]([CH3:11])[OH:10])=[O:6])[CH2:3][OH:4].[F:29][C:30]([C:31]([OH:33])=[O:32])([F:35])[F:34]Participants
3
Procedure
65.7 g of BOC-Ser-Thr-OBzl are dissolved in 100 ml of 90% strength trifluoroacetic acid and the solution is left for one hour at 20° C. It is then added dropwise to 1000 ml of dry either whilst stirring and the mixture is stirred for one hour and left to stand overnight at -10° C. The resulting precipitate is filtered off and washed three times with dry ether and dried in vacuo over sodium hydroxide; melting point 128°-129° C.; Rf7 = 0.65; Rf4 = 0.50 (on silica gel).
Workup
- additionIt is then added dropwise to 1000 ml
- customof dry
- stirringthe mixture is stirred for one hour
- waitleft
- waitto stand overnight at -10° C