反应详情

温度

25 °C

The following are weighed into a 2 liter multinecked flask equipped with a stirrer, thermometer, dropping funnel and distilling section: 530 ml of aqueous saturated K2SO4 solution (10% strength, from previous batches), 206 g of KOH flakes (85%, 3.12 mol) and 500 ml of ethanol 95% strength (recovery from previous batches). The mixture is then heated to boiling until a clear solution is obtained. Over a period of 1 h, 270.5 g of diethyl diethylmalonate (1.25 mol) are added dropwise, and over a period of 5-6 hours from 160-180 ml of ethanol are removed by distillation. The batch is cooled. Then, with cooling (to about 25° C.), a 177 g amount of conc. H2SO4 (96% strength, 1.73 mol), which amount beforehand is diluted with about the same amount of H2 O, is added gradually until the pH has dropped to a level of from 1-2.

1. customequipped with a stirrer
2. distillationdistilling section
3. temperatureThe mixture is then heated
4. customis obtained
5. customover a period of 5-6 hours from 160-180 ml of ethanol are removed by distillation
6. temperatureThe batch is cooled
7. additionis added gradually until the pH
8. additionhas dropped to a level of from 1-2