反应详情

To a stirred solution of 1928 g (32.1 mol) of ethylenediamine in 2 liters of absolute ethanol was added a solution of 3130 g (12.8 mol) of ethyl α-bromophenylacetate in 4 liters of absolute ethanol at such a rate so as to maintain reflux (~45 minutes addition time). The mixture was allowed to cool to ambient temperature and then concentrated to a thick yellow slurry. The slurry was stirred with 2 liters of chloroform, filtered, and the solid washed thoroughly with chloroform (total of 8 liters). The filtrate was concentrated to near dryness and the resulting residue stirred for a short time with 2 liters of isopropanol. The solid was collected by filtration, washed with 4 liters of isopropanol, and dried to give 1224 g (54%) of 3-phenyl-2-piperazinone. This material was used as such in the next step. [Pure material could be obtained by recrystallization from benzene and then from acetone to give a white solid (mp. 139.0°-139.5° C. ).]

1. temperatureto maintain
2. temperaturereflux
3. addition(~45 minutes addition time)
4. concentrationconcentrated to a thick yellow slurry
5. filtrationfiltered
6. washthe solid washed thoroughly with chloroform (total of 8 liters)
7. concentrationThe filtrate was concentrated
8. stirringthe resulting residue stirred for a short time with 2 liters of isopropanol
9. filtrationThe solid was collected by filtration
10. washwashed with 4 liters of isopropanol
11. customdried