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

Participants

Reaction Steps

3.0 g of tert.-butyl (4S)-1-n-butyl-2-oxo-imidazolidine-4-carboxylate, 1.4 g of potassium tert.-butoxide, (2S)-3-benzoylthio-2-methylpropionyl chloride (prepared from 2.8 g of (2S)-3-benzoylthio-2-methylpropionic acid and 10 ml of thionyl chloride) and 40 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)). 3.8 g of tert.-butyl (4S)-1-n-butyl-3-[(2S)-3-benzoylthio-2-methylpropionyl]-2-oxo-imidazolidine-4-carboxylate are obtained as colorless syrup.

Provenance & Evidence