反应详情

KOH (7.0 g, 0.105 mol) was added slowly to a hot solution of the diester from Step C (14 g, 0.046 mol) in ethylene glycol (50 mL) with stirring under Ar. The reaction mixture was heated at reflux for 3 hr, cooled, acidified to pH=2 with HCl, diluted with H2O (150 mL), and extracted with benzene (3×50 mL). The organic layers were combined, washed with dilute NaHCO3 solution (2×100 mL), H2O (2×50 mL), dried, filtered, and concentrated to dryness to give the title compound after chromatography on SiO2 eluting with CHCl3:MeOH, 40:1.

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 3 hr
3. temperaturecooled
4. extractionextracted with benzene (3×50 mL)
5. washwashed with dilute NaHCO3 solution (2×100 mL), H2O (2×50 mL)
6. customdried
7. filtrationfiltered
8. concentrationconcentrated to dryness