反应详情

15 ml of trifluoroacetic acid are added to 4.0 g of tert.-butyl (4S)-1-methyl-3-[(2S)-3-benzoylthio-2-methylpropionyl]-2-oxo-imidazolidine-4-carboxylate, and the mixture is stirred at room temperature for 2 hours. The reaction mixture is condensed under reduced pressure. Toluene is added to the residue, and said mixture is again condensed under reduced pressure. The residue thus obtained is recrystallized from a mixture of ethyl acetate and n-hexane. 3.2 g of (4S)-1-methyl-3-[(2S)-3-benzoylthio-2-methylpropionyl]-2-oxo-imidazolidine-4-carboxylic acid is thereby obtained as colorless syrup. The physico-chemical properties of this product are identical with those of the sample obtained in Example 1-(5).

1. customcondensed under reduced pressure
2. customcondensed under reduced pressure
3. customThe residue thus obtained
4. customis recrystallized from a mixture of ethyl acetate and n-hexane