反应详情

温度

75 °C

Cyclohexylurea (1.3 g, 9 mmol) was dissolved in sodium ethoxide in ethanol (21% w/w, 3 mL) at 75° C. To this solution 5 was added (0.5 g, 1.1 mmol) in one lot. The resulting mixture was stirred at 75° C. for 5 min, then cooled quickly to 40-50° C. TFA (0.5 mL) was added and then 5% aqueous HCl (1N, 0.6 mL). After stirring at room temperature for 1 hr, the mixture was left overnight at 4° C. The solid separated was filtered and refluxed in ethyl acetate (4 mL) for 20 min. The mixture was allowed to cool to room temperature, filtered and the crude product was purified by silica gel chromatography using hexane-ethyl acetate (1:1). Yield: 0.27 g, 45%.

1. temperaturecooled quickly to 40-50° C
2. stirringAfter stirring at room temperature for 1 hr
3. waitthe mixture was left overnight at 4° C
4. customThe solid separated
5. filtrationwas filtered
6. temperaturerefluxed in ethyl acetate (4 mL) for 20 min
7. temperatureto cool to room temperature
8. filtrationfiltered
9. customthe crude product was purified by silica gel chromatography