反应详情

温度

90 °C

The foregoing compound 22 (17.5 g, 31.8 mmoles) and a 1M solution of N2H4.H2O in dioxane/ethanol 4:1 (35 mL, 2 equivalents) are stirred and heated at about 90° C. After 3 hours, a yellow precipitate is formed, and the mixture is allowed to cool to room temperature. The precipitate is filtered and the filtrate is evaporated to yield an oil. The oil and the precipitate are united and heated with ethanol (310 mL) and conc. HCl (18.6 mL) at 90° C. for 3 hours. After cooling, phthalhydrazide is filtered and the solution is evaporated. Dissolving in water, filtration, evaporation, dissolving in ethanol, evaporating again and drying (oil pump) yields a yellow foam: 11.5 g (about 100%). Thin layer chromatography (ethanol/ammonia 80/20) shows a second spot (presumably some ester cleaved). The compound 23 is utilized for the next step without further purification.

1. customa yellow precipitate is formed
2. temperatureto cool to room temperature
3. filtrationThe precipitate is filtered
4. customthe filtrate is evaporated
5. customto yield an oil
6. temperatureAfter cooling
7. filtrationphthalhydrazide is filtered
8. customthe solution is evaporated
9. dissolutionDissolving in water
10. filtrationfiltration, evaporation
11. dissolutiondissolving in ethanol
12. customevaporating again
13. customdrying (oil pump)
14. customyields a yellow foam
15. customThe compound 23 is utilized for the next step without further purification