Synthesis of hybrid molecules based on thioglycolurils and 1,2,5-oxadiazoles via the Eschenmoser sulfide contraction

A simple synthesis of novel hybrid molecules containing methylidenehexahydroimidazo[4,5-d]imidazol-2(1H)-one and 1,2,5-oxadiazole moieties is based on the Eschenmoser sulfide contraction involving alkylative precoupling of thioglycolurils with 3(4)-bromoacetyl-1,2,5-oxadiazoles. The proposed method does not require using toxic PPh₃ for sulfur extrusion. The synthesized compounds may serve as platforms for constructing both new bioactive and new high- energy compounds.