反应详情

To a solution of 50 mg of N-[2-(1-naphthylmethyl)-3-morpholinocarbonyl)propionyl]-L-histidine hydrazide in 1 ml of N,N-dimethylformamide were added successively 0.068 ml of a dry 5.1N-hydrogen chloride in N,N-dimethylformamide solution and 0.017 ml of isoamyl nitrite at -20° C. with stirring. After disappearance of hydrazide compound, the reaction mixture was cooled to -30° C., and the reaction mixture was neutralized by adding 0.048 ml of triethylamine to prepare a solution of N-[2-(1-naphthylmethyl)-3-(morpholinocarbonyl)propionyl]-L-histidine azide. The cold azide solution was added dropwise to a solution of 25 mg of isopropyl (2RS, 3S)-3-amino-2-hydroxy-5-methylhexanoate hydrochloride and 0.032 ml of triethylamine in 2 ml of N,N-dimethylformamide under ice-cooling, and the mixture was stirred for 16 hours. A 5% aqueous sodium bicarbonate solution was added to the reaction mixture, and the mixture was extracted with ethyl acetate, washed with a saturated sodium chloride, dried over anhydrous magnesium sulfate, and evaporated under reduced pressure. The residue was purified by preparative silica gel thin layer chromatography (developing solvent: chloroform/methanol=5/1 by volume Rf2 =0.53 to obtain 4 mg of isopropyl (2RS, 3S)-3-{N-[2-(1-naphthylmethyl)-3-(morpholinocarbonyl)propionyl]-L-histidyl}amino-2-hydroxy-5-methylhexanoate as a white powder.

1. temperaturecooling
2. extractionthe mixture was extracted with ethyl acetate
3. washwashed with a saturated sodium chloride
4. dry with materialdried over anhydrous magnesium sulfate
5. customevaporated under reduced pressure
6. customThe residue was purified by preparative silica gel thin layer chromatography (