反应详情

The substance [24] was dissolved in ethanol (200 ml). 1 N NaOH (240 ml, 1.2 molar excess) was added dropwise at 0° C. and the mixture was stirred at room temperature. After two hours, 1 N NaOH (20 ml) was added and the mixture was further stirred for 30 minutes. The reaction mixture was neutralized with 1 N HCl (60 ml) at 0° C., and the ethanol was distilled off in vacuo. After twice washing the aqueous layer with ether (100 ml), 1 N HCl (200 ml) was added thereto at 0° C. The precipitate thus formed was filtered, washed completely and dried in vacuo. Recrystallization was effected from ethyl acetate (450 ml)-hexane to crystallize the substance [25] (47.92 g, yield: 83.8%).

1. stirringthe mixture was further stirred for 30 minutes
2. distillationthe ethanol was distilled off in vacuo
3. washAfter twice washing the aqueous layer with ether (100 ml), 1 N HCl (200 ml)
4. additionwas added
5. customat 0° C
6. customThe precipitate thus formed
7. filtrationwas filtered
8. washwashed completely
9. customdried in vacuo
10. customRecrystallization