反应详情

2 g. of the ethyl ester product from part (d) are dissolved in 100 ml. of ethanol. 0.5 g. of Lindlar catalyst are added and the reaction mixture is stirred for four hours at room temperature under two atmospheres of hydrogen. At intervals the reaction mixture is filtered. After completion of the slow absorption of hydrogen, the reaction solution is flooded with nitrogen and then heated to a boil. This mixture is filtered while hot and after cooling 1 g. of crude product is obtained from the filtrate. Recrystallization from water yields as white crystals purified 1-[(phenylmethylene)amino]-2,3-piperazinedione; m.p. 229°-231°.

1. filtrationAt intervals the reaction mixture is filtered
2. customAfter completion of the slow absorption of hydrogen
3. temperatureheated to a boil
4. filtrationThis mixture is filtered while hot and
5. temperatureafter cooling 1 g
6. customof crude product is obtained from the filtrate
7. customRecrystallization from water
8. customyields as white crystals
9. custompurified 1-[(phenylmethylene)amino]-2,3-piperazinedione