Trifluoroacetic acid → Z-Val-pro-OH

HRID 1636964Notes

Reaction equation

FC(F)(F)C(O)=O.C([O:12][C:13](=[O:36])[C@@H:14]1[CH2:18][CH2:17][CH2:16][N:15]1[C:19](=[O:35])[C@H:20]([CH:32]([CH3:34])[CH3:33])[NH:21][C:22]([O:24][CH2:25][C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)=[O:23])(C)(C)C>C(Cl)Cl>[CH2:25]([O:24][C:22]([NH:21][C@H:20]([C:19]([N:15]1[CH2:16][CH2:17][CH2:18][C@H:14]1[C:13]([OH:36])=[O:12])=[O:35])[CH:32]([CH3:34])[CH3:33])=[O:23])[C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1

Participants

Conditions

Temperature: 0 °C

Procedure

Trifluoroacetic acid (200 ml) was added to a mixture of N-benzyloxycarbonyl-L-valyl-L-proline tert-butyl ester (80.0 g) in methylene chloride ((300 ml) at 0° C. over approximately 30 minutes. After stirring at 0° C. for one hour, the reaction mixture was allowed to rise to ambient temperature and stirred an additional 3 hours. The reaction mixture was then concentrated under vacuum and reconcentrated four times from toluene to remove residual trifluoroacetic acid. The resulting viscous oil was dried under vacuum for 16 hours. The crude product was purified on by chromatography on silica gel, using methylene chloride as eluant, to give N-benzyloxycarbonyl-L-valyl-L-proline (A) (63.6 g) as a pale yellow viscous oil; NHR (d6 -DMSO): 0.92(2d,6H), 1.65-2.05(2 m,4H), 2.25(m,1H), 3.60(m,1H), 3.80(m,1H), 4.05(dd,1H), 4.25(m,1H), 5.02(2d,2H), 7.35(m,5H), 7.50(d,1H).

Workup

customto rise to ambient temperature
stirringstirred an additional 3 hours
concentrationThe reaction mixture was then concentrated under vacuum
customto remove residual trifluoroacetic acid
customThe resulting viscous oil was dried under vacuum for 16 hours
customThe crude product was purified on by chromatography on silica gel

Sources & evidence

ORD record: ord-b0f90c1483c748f7946c7191c26d41b9
Source dataset: uspto-grants-2000_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06037363

Reaction notes

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