Facile synthesis of hexahydropyrazino[2,3-e]pyrazines from 3-aminomethyl-1,2,4-triazoles

The cyclocondensation of aminomethyl-1,2,4-triazoles and glyoxal gives hexahydropyrazino[2,3-e]pyrazines in good yields. H-1 and C-13 NMR spectra of the title compounds are described and the molecular structure of 4a,5,6,10a,11,12-hexahydro-(4aR,10aR)-[1,2,4]triazolo[1,5-a][1,2,4]triazolo[1',5':1,6]pyrazino[2,3-e]pyrazine was established by single crystal X-ray analysis. (C) 2016 Elsevier Ltd. All rights reserved.