反应详情

A mixture of 1020 ml (1041 g, 8.00 mol) of ethyl acetoacetate, 960 ml (824 g, 8.40 mol) of mesityl oxide, 1000 ml of heptane, 600 ml of toluene, and 175 g of zinc chloride was heated at reflux in a 5000 ml round bottom flask while stirring. The flask was equipped with a Dean-Stark trap and drying tube. After 24 h, an additional 25 g of zinc chloride was added and refluxing continued for 36 h. After cooling, the reaction mixture was washed with 1500 ml of water, 5% sodium bicarbonate solution (2×1000 ml), and another 1500 ml of water. Removal of solvent by evaporation yielded 979 g of crude product. Distillation of the crude product provided 453.5 g of the desired ester which represents 27.0% yield. Distillation was at 124°-5° C. (3.0 torr).

1. temperaturewas heated
2. temperatureat reflux in a 5000 ml round bottom flask
3. customThe flask was equipped with a Dean-Stark trap
4. customdrying tube
5. additionan additional 25 g of zinc chloride was added
6. temperaturerefluxing
7. waitcontinued for 36 h
8. temperatureAfter cooling
9. washthe reaction mixture was washed with 1500 ml of water, 5% sodium bicarbonate solution (2×1000 ml)
10. customRemoval of solvent
11. customby evaporation
12. customyielded 979 g of crude product
13. distillationDistillation of the crude product