反应详情

温度

0 °C

To a solution of 70.0 ml of diethyl malonate dissolved in 400 ml of dry ethanol was added 10.0 g of metallic sodium. The reaction mixture was stirred for 30 minutes and cooled to 0° C; and 66.5 g of 3,4-dimethylbenzyl chloride was added thereto. This reaction mixture was stirred at a room temperature for another 1 hour, heated at the boiling temperature for 4 hours and concentrated under a reduced pressure. The residue was dissolved in ethyl ether and the solution was washed with water. After further concentration under a reduced pressure, the organic phase was combined with 500 ml of water and 170 g of KOH; and this mixture was heated at the boiling temperature for 24 hours. The mixture was concentrated under a reduced pressure to about one half volume; then 200 ml of 98% sulfuric acid was added slowly thereto. The resultant solution was heated at the boiling temperature for 24 hours, extracted twice with 300 ml of ethyl acetate. The organic solvent was distilled off under a reduced pressure and the residue was recrystallized from boiling hexane to obtain 42.1 g of the title compound as a white solid(yield: 55%).

1. stirringThis reaction mixture was stirred at a room temperature for another 1 hour
2. temperatureheated at the boiling temperature for 4 hours
3. concentrationconcentrated under a reduced pressure
4. dissolutionThe residue was dissolved in ethyl ether
5. washthe solution was washed with water
6. concentrationAfter further concentration under a reduced pressure
7. temperatureand this mixture was heated at the boiling temperature for 24 hours
8. concentrationThe mixture was concentrated under a reduced pressure to about one half volume
9. additionthen 200 ml of 98% sulfuric acid was added slowly
10. temperatureThe resultant solution was heated at the boiling temperature for 24 hours
11. extractionextracted twice with 300 ml of ethyl acetate
12. distillationThe organic solvent was distilled off under a reduced pressure
13. customthe residue was recrystallized