Condensation reactions of 2,5-piperazinediones with carbonyl compounds

In this work the aldol condensation reactions of 2,5-piperazinediones with carbonyl compounds were investigated. It was found that condensation of title compounds in the system CH3COONa/(CH3CO)2O yielded 3,6-bis(arvlidene)-2,5-piperazinediones. These compounds could be easily converted to a-amino acid by reducing with zinc powder and hydrolyzing with concentrated acid or Ba(0H)2 solution. Interaction of l,4-dibenzyl-2,5-piperazinedione with 4-substituted benzaldehydes does not lead to the formation of the benzylidene derivative because of steric hindrance of N-benzyl groups. The effect of different reaction conditions were studied. The purity of the obtained compounds was controlled by thin layer chromatography. The structure was Droved bv the data 'H NMR and IR spectraVytauto Didžiojo universitetasŠvietimo akademij