反应详情

To a suspension of 24.78 g (165 mmol) of benzylurea and 25 ml (165 mmol) of diethyl malonate in 84 ml of methanol, 40.2 ml (165 mmol) of a 4.1M sodium methylate solution was added at room temperature, followed by refluxing for 16 hours. After the reaction mixture was cooled, the solvent was distilled off. After the residue was dissolved in water and insoluble substances were filtered out, the filtrate was adjusted to pH 3-4 by adding concentrated hydrochloric acid. The resulting precipitate was collected by filtration, washed with water and n-hexane-diethyl ether and dried to yield 32.12 g (89.2%, white crystal) of the desired product.

1. additionwas added at room temperature
2. temperatureby refluxing for 16 hours
3. temperatureAfter the reaction mixture was cooled
4. distillationthe solvent was distilled off
5. dissolutionAfter the residue was dissolved in water
6. filtrationinsoluble substances were filtered out
7. additionby adding concentrated hydrochloric acid
8. filtrationThe resulting precipitate was collected by filtration
9. washwashed with water and n-hexane-diethyl ether
10. customdried