(2S)-3-benzoylthio-2-methylpropionyl chloride → tert.-butyl (4S)-1-benzyl-3-[(2S)-3-benzoylthio-2-methylpropionyl]-2-oxo-imidazolidine-4-carboxylate

Participants

Reaction Steps

27.6 g of tert.-butyl (4S)-1-benzyl-2-oxo-imidazolidine-4-carboxylate, 11.2 g of potassium tert.-butoxide, (2S)-3-benzoylthio-2-methylpropionyl chloride (prepared from 22.4 g of (2S)-3-benzoylthio-2-methylpropionic acid and 25 ml of thionyl chloride) and 200 ml of tetrahydrofuran are treated in the same manner as described in Example 2-(2). Then, the oily residue obtained is purified by silica gel chromatography (Solvent, toluene-ethyl acetate(20:1)) and triturated with n-hexane. 34.1 g of tert.-butyl (4S)-1-benzyl-3-[(2S)-3-benzoylthio-2-methylpropionyl]-2-oxo-imidazolidine-4-carboxylate are obtained as colorless crystals. Yield: 70.7%

Provenance & Evidence