Triethylamine → isopropyl (2RS, 3S)-3-(N-benzyloxycarbonyl-L-alanyl)amino-2-hydroxy-5-methylhexanoate

Participants

Reaction Steps

To a solution of 61 mg of N-benzyloxycarbonyl-L-alanine and 79 mg of isopropyl (2RS, 3S)-3-amino-2-hydroxy-5-methylhexanoate hydrochloride in 5 ml of N,N-dimethylformamide were added successively 0.071 ml of diphenylphosphoryl azide and 0.125 ml of triethylamine with stirring under ice-cooling, and the mixture was stirred overnight. The reaction mixture was evaporated under reduced pressure, and to the residue was added a 5% aqueous sodium bicarbonate solution. The mixture was extracted with ethyl acetate and the ethyl acetate layer was washed with water, dried over anhydrous magnesium sulfate and evaporated under reduced pressure. The residue was purified with silica gel flash column chromatography (eluent: chloroform/methanol=20/1 by volume) to obtain 56 mg of isopropyl (2RS, 3S)-3-(N-benzyloxycarbonyl-L-alanyl)amino-2-hydroxy-5-methylhexanoate as a colorless viscous oil.

Provenance & Evidence