Triethylamine → N-[2-(1-naphthylmethyl)-3-(phenethylcarbamoyl)propionyl]-L-histidyl-L-leucinal semicarbazone

Participants

Reaction Steps

To a solution of 221 mg of (±)-2-(1-naphthylmethyl)-3-(phenethylcarbamoyl)propionic acid and 400 mg of bis-(p-toluenesulfonic acid) salt of L-histidyl-L-leucinal semicarbazone in 5 ml of dry N,N-dimethylformamide were successively added dropwise 202 mg of diphenylphosphoryl azide and 0.28 ml of triethylamine under ice-cooling, and then the mixture was stirred for 15 hours. The reaction mixture was concentrated under reduced pressure, and a 5% aqueous sodium bicarbonate solution was added to the residue. The mixture was extracted with ethyl acetate. The organic layer was washed with a saturated sodium chloride aqueous solution, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: chloroform/methanol=10/1 by volume) to obtain 71 mg of N-[2-(1-naphthylmethyl)-3-(phenethylcarbamoyl)propionyl]-L-histidyl-L-leucinal semicarbazone (isomer A) and 166 mg of isomer B.

Provenance & Evidence