反应详情

The crude material 23 (11.5 g, about 31 mmoles since some solvent left) is dissolved in ethanol (150 mL) and 2N NaOH (150 mL) and stirred at room temperature for 3 hours. The mixture is neutralized with conc. HCl (about 25 mL) with cooling, then acidified (HCl). After evaporation and drying, the residue is dissolved in ethanol, filtered through millipore, and evaporated again. Dissolving in water, filtration, and evaporation yields a solid (11 g, 2 g more than theory). This is dissolved in isopropanol (130 mL) and treated with propylene oxide (6.5 mL, 3 equivalents). Crude 24 (7.2 g, somewhat more than theory) is collected. Thin layer chromatography (ethanol/NH4OH 80/20 revelation ninhydrin) indicates the presence of some decarboxylated product. The compound 24 is used without further purification. Recrystallization from water/ethanol is possible. Caution: no heating!

1. temperaturewith cooling
2. customAfter evaporation
3. customdrying
4. dissolutionthe residue is dissolved in ethanol
5. filtrationfiltered through millipore
6. customevaporated again
7. dissolutionDissolving in water
8. filtrationfiltration, and evaporation
9. customyields a solid (11 g, 2 g more than theory)
10. customCrude 24 (7.2 g, somewhat more than theory) is collected
11. customThe compound 24 is used without further purification
12. customRecrystallization from water/ethanol