1976 年 34 巻 6 号 p. 425-426
Facile preparations of 4-substituted-2, 6-piperazinediones from N-substituted-iminodiacetic acids by the ring closure were studied. The crude piperazinediones were obtained by extraction of the reaction mixture with an appropriate solvent and purified by recrystallization. Isolation of the piperazinediones by sublimation, however, was found to be troublesome. 4-Phenyl- and 4-benzyl--2, 6-piperazinediones were prepared in satisfactory yields.