反应详情

Diethyl N-(1,4-dioxaspiro[4.5]decen-8-yl)aminomethylenemalonate (53 g) in 100 ml of Dowtherm is added to 400 ml of Dowtherm at reflux and the mixture is heated at 250° for 45 minutes. The low boiling distillate is collected in a Dean-Stark trap. After cooling to room temperature, the mixture is evaporated to dryness in vacuo, and the residue is triturated with Et2O to give ethyl 4-hydroxy-6-oxo-5,6,7,8-tetrahydroquinoline-3-carboxylate ethylene ketal.

1. temperatureat reflux
2. temperaturethe mixture is heated at 250° for 45 minutes
3. distillationThe low boiling distillate is collected in a Dean-Stark trap
4. customthe mixture is evaporated to dryness in vacuo
5. customthe residue is triturated with Et2O