A new and versatile Ugi/SNAr synthesis of fused 4,5-dihydrotetrazolo[1,5-a]quinoxalines

A combinatorial synthetic route yielding fused tetrazolo[1,5-a]quinoxalines is described. The use of 2-fluorophenyliso-cyanide in the Ugi-tetrazole reaction (tetrazole-U-4CR) followed by a nucleophilic aromatic substitution (SNAr) affords the tri-cylic tetrazolo[1,5-a]quinoxaline moiety in good yields and with high diversity. (c) 2006 Elsevier Ltd. All rights reserved.