Pyrazine Chemistry. IV. Oxidation of 3,6-Dibenzylpiperazine-2,5-diones

Abstract

The autoxidation of (±) cis- and trans-3,6-dibenzyl-1,4- dimethylpiperazine-2,5-diones (6) and (8) has been shown to give (±)-6- benzyl-1,4-dimethylpiperazine-2,3,5-trione (12). Oxidation of a (2) cis-trans mixture of 1,4-diacetyl-3,6-dibenzylpiperazine-2,5-diones, (5) and (7), with elemental sulfur was shown to give (±)-(Z)-1-acetyl- 6-benzyl-3-benzylidenepiperazine-2,5-dione (10).