Trifluoroacetic acid → L-Valyl-N-Methyl-L-Alanyl-L-Alanine Benzyl Ester
Reaction equation
[CH2:1]([O:8][C:9](=[O:33])[C@H:10]([CH3:32])[NH:11][C:12](=[O:31])[C@H:13]([CH3:30])[N:14]([C:16](=[O:29])[C@H:17]([CH:26]([CH3:28])[CH3:27])[NH:18]C(OC(C)(C)C)=O)[CH3:15])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.FC(F)(F)C(O)=O.C(=O)(O)[O-].[Na+]>ClCCl>[CH2:1]([O:8][C:9](=[O:33])[C@H:10]([CH3:32])[NH:11][C:12](=[O:31])[C@H:13]([CH3:30])[N:14]([C:16](=[O:29])[C@H:17]([CH:26]([CH3:28])[CH3:27])[NH2:18])[CH3:15])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Participants
Conditions
- Temperature
- -15 °C
Procedure
A stirred solution of 17 g (0.0367 mole) Boc-L-valyl-N-methyl-L-alanyl-L-alanine benzyl ester in 170 ml of dry dichloromethane was cooled at -10° C. as 85 ml of trifluoroacetic acid, previously cooled at -15° C., was added. After 16 hours at -5° C., the reaction was carefully poured with good stirring into a mixture of 93 g of sodium bicarbonate, ice, and 250 ml of dichloromethane. The organic layer was separated and the aqueous layer was extracted with another 75 ml of dichloromethane. The combined organic layers were washed with 3×75 ml of saturated sodium bicarbonate solution, dried over magnesium sulfate, and evaporated to give 12.8 g (96% of theory) of crude product which was used in step 5 without further purification. FAB m.s. showed a molecular ion peak at 364.
Workup
- additionwas added
- additionthe reaction was carefully poured
- customThe organic layer was separated
- extractionthe aqueous layer was extracted with another 75 ml of dichloromethane
- washThe combined organic layers were washed with 3×75 ml of saturated sodium bicarbonate solution
- dry with materialdried over magnesium sulfate
- customevaporated
- customto give 12.8 g (96% of theory) of crude product which
- customwas used in step 5 without further purification
Sources & evidence
- ORD record
- ord-b21d5bef50904eb5b4b794507c6b6a37
- Source dataset
- uspto-grants-1993_08
- Patent number
- US05236899
Reaction notes
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