5-Amino-Substituted 2-Methoxy-1,3,4-oxadiazoles as Common Precursors Toward 1,3,4-Oxadiazol-2(3 H)-ones and 1,2,4-Triazolidine-3,5-diones

Abstract

The divergent synthesis of two different classes of azole derivatives using 5-amino-substituted 2-methoxy-1,3,4-oxadiazoles as common substrates is reported. Depending on the reaction time and temperature, alkylation of oxadiazoles with excess alkyl halides proceeds with high regioselectivity toward 1,3,4-oxadiazolones and 1,2,4-triazolidine-3,5-diones. This operationally simple protocol enables rapid access to a diverse set of isomeric azoles using minimum synthetic steps and easily accessible oxadiazole key precursors.