反应详情

To a solution of 80.0 mg (0.222 mmol) of the carboxylic acid from Example 21A in 0.89 ml of DMF and 1.78 ml of 1,4-dioxane were added, at 60° C., 108 mg (0.666 mmol) of 1,1′-carbonyldiimidazole, and the mixture was stirred for 3 h. Subsequently, the mixture was admixed with 52.4 mg (0.333 mmol; 75% purity) of isopropyl N′-hydroxyimidocarbamate [G. Zinner, G. Nebel, Arch. Pharm. 1970, 303, 385-390] and then stirred at RT for 2 h and then at 120° C. for 2 h. The reaction solution was concentrated under reduced pressure and purified directly by means of preparative HPLC. Yield: 22.6 mg (22% of theory)

1. waitat 120° C. for 2 h
2. concentrationThe reaction solution was concentrated under reduced pressure
3. custompurified directly by means of preparative HPLC