Reactivity of 1-(2-nitrophenyl)-5-aminopyrazoles under basic conditions and synthesis of new 3-, 7-, and 8-substituted pyrazolo[5,1-c][1,2,4]benzotriazine 5-oxides,as benzodiazepine receptor ligands

The reaction of 1-(2-nitrophenyl)-5-aminopyrazoles under basic conditions has been reinvestigated and the structures of the obtained pyrazolo5,1-c]1,2,4]benzotriazine 5-oxides confirmed by spectroscopic means. In particular the different aromatic nucleophilic attack on 8-chloro derivatives 4a and 6a and 7-nitro derivatives 11a and 12a was determined. From these latter compounds unexpected (phenyl-ONN-azoxy)pyrazoles were isolated.