Trifluoroacetic acid → Trifluoroacetic acid
Reaction equation
[NH:1](C(OC(C)(C)C)=O)[CH2:2][C:3]([NH:5][CH2:6][C:7]([NH:9][C@H:10]([C:18]([NH:20][CH2:21][C:22]([OH:24])=[O:23])=[O:19])[CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:8])=[O:4].[F:32][C:33]([F:38])([F:37])[C:34]([OH:36])=[O:35]>>[F:32][C:33]([F:38])([F:37])[C:34]([OH:36])=[O:35].[NH2:1][CH2:2][C:3]([NH:5][CH2:6][C:7]([NH:9][C@H:10]([C:18]([NH:20][CH2:21][C:22]([OH:24])=[O:23])=[O:19])[CH2:11][C:12]1[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=1)=[O:8])=[O:4]Participants
4
Procedure
Boc-Gly-Gly-Phe-Gly-OH (200 mg) was dissolved in trifluoroacetic acid (4 ml) and stirred for 1.5 hours. The solvent was evaporated, and the residue was subjected to azeotropic distillations twice with methanol (10 ml) and twice with ethanol (10 ml) and washed with ether to obtain trifluoroacetic acid salt of Gly-Gly-Phe-Gly-OH (225 mg).