反应详情

温度

0 °C

To a solution of the carboxylic acid of Example 9 or 16 (6b, 354 mg, 1.28 mmol) in tetrahydrofuran (10 mL) were added triethylamine (0.216 mL) and isobutyl chloroformate (208 μl) under ice-cooling, followed by agitating at 0° C. for 15 minutes. To the reaction solution were added a solution of propionohydrazide (161 mg, prepared following a procedure analogous to Reference Example 3 and Reference Example 6) in tetrahydrofuran (3 mL) at 0° C., followed by stirring at room temperature for 1 hour, and then concentrating under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate=1/1-0/1) to afford 425 mg of the title compound (yield 96%).

1. temperaturecooling
2. customprepared
3. customat 0° C.
4. stirringby stirring at room temperature for 1 hour
5. concentrationconcentrating under reduced pressure
6. customThe resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate=1/1-0/1)