Aspects of heterocyclisation reactions mediated by nucleophilic interaction of aromatic nitro groups with ortho heterocumulene side chains

2002 ARKIVOC  
Evidence is presented for the involvement of ketene intermediates in the thermal transformations of ethyl 4-nitro-1H-imidazol-5-ylethanoates into 4H-imidazo[4,5-c]isoxazole derivatives. Direct heterocyclisation of a 1-(4-nitro-1H-imidazol-5-yl)-3-phenylcarbodiimide intermediate is proposed to account for the reaction of a triphenyl N-(4-nitro-1H-imidazol-5-yl)phosphinimine with phenyl isocyanate exemplifying a new, flexible, and potentially general route to 2-aryl-2H,
more » ... azo[4,5-d][1,2,3]triazoles.
doi:10.3998/ark.5550190.0003.308 fatcat:t2ybarylanazrlniyb6qgmnjha