Synthesis of [1,2,4]Triazolo[4,3-α]piperazines via Highly Reactive Chloromethyloxadiazoles

[reaction: see text] A concise, modular approach for the synthesis of [1,2,4]triazolo[4,3-alpha]piperazines via condensation of highly reactive chloromethyloxadiazoles with ethylenediamines is described. NMR studies of this reaction provide evidence that suggests a novel activation mechanism for electron-deficient chloromethyloxadiazoles.