反应详情

To a solution of 23 g (1g-atom) sodium metal in 500 ml absolute ethanol were added at room temperature 35 g (0.3 mole) butyl-urea and 48 g (0.3 mole) malonic acid-diethylester. The alcohol was then distilled off in an oil bath held at 120° C and the residue maintained at this temperature for about 16 hours. The residue was then cooled and dissolved in about 300 ml water, stirred with activated carbon and the solution filtered. The clear filtrate was acidified by the addition of concentrated hydrochloric acid to produce 38 g 1-butyl-barbituric acid, representing a yield of 68%. The substance had, after recrystallization from benzene, a melting point of 107°-108° C.

1. distillationThe alcohol was then distilled off in an oil bath
2. customheld at 120° C
3. temperaturethe residue maintained at this temperature for about 16 hours
4. temperatureThe residue was then cooled
5. dissolutiondissolved in about 300 ml water
6. filtrationthe solution filtered
7. additionThe clear filtrate was acidified by the addition of concentrated hydrochloric acid