反应详情

To a suspension of 1.00 g of (±)-2-(1-naphthylmethyl)-3-(phenethylcarbamoyl)propionic acid and 0.67 g of L-histidine methyl ester dihydrochloride in 8 ml of N,N-dimethylformamide were added 0.72 ml of diphenylphosphoryl azide and 1.27 ml of triethylamine under ice-cooling, and the mixture was stirred for 16 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 water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel flash column chromatography (eluent: chloroform/methanol=15/1 by volume) to obtain 1.36 g of N-[(±)-2-(1-naphthylmethyl)-3-(phenethylcarbamoyl)propionyl]-L-histidine methyl ester.

1. temperaturecooling
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. additiona 5% aqueous sodium bicarbonate solution was added to the residue
4. extractionThe mixture was extracted with ethyl acetate
5. washThe organic layer was washed with water
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by silica gel flash column chromatography (eluent: chloroform/methanol=15/1 by volume)