反应详情

温度

-20 °C

To a solution of acetylalanylalanylproline (3 mmole) and N-methylmorpholine (3 mmole) in dry tetrahydrofuran (110 ml) at -20° to -25° C. is added isobutyl chloroformate (3 mmole) and stirred at -20° C. for 10 minutes. A solution of 2-azaalanylalanine ethyl ester (3 mmole) in tetrahydrofuran (15 ml) is added dropwise. The resulting mixture is allowed to warm to room temperature over a period of 1 hour and stirred overnight. The precipitate is filtered off and the filtrate is concentrated to dryness. Chromatography on silica gel (70 gm) and elution with 8% methanol in chloroform gives acetylalanylalanylprolyl-2-azaalanylalanine ethyl ester.

1. temperatureto warm to room temperature over a period of 1 hour
2. stirringstirred overnight
3. filtrationThe precipitate is filtered off
4. concentrationthe filtrate is concentrated to dryness
5. washChromatography on silica gel (70 gm) and elution with 8% methanol in chloroform