New phenanthrene systems: spiro-fused tricyclic phenanthro-1,2,4-triazolo-[4,3-d]-1,2,4-triazines and -[3,4-d]-1,2,5-oxadiazines: ring expansions of N-methylphenanthroazoliums

Abstract

New routes to substituted phenanthro[9,10-e]-1,2,4-triazines and phenanthro[9,10-c]-1,2,5-oxadiazines are described. Cycloadditions of these with C-phenyl-N-p-nitrophenylnitrile imide [IUPAC name: 2-benzylidene-1-(p-nitrophenyl)hydrazin-2-ium-1-ide] gave new substituted spiro-tricyclic phenanthro-1,2,4-triazolo[4,3-d][1,2,4]triazines and phenanthro-1,2,4-triazolo[3,4-d][1,2,5]oxadiazines. An X-ray crystal structure is reported on 7,10-diphenyl-5-(4′-nitrophenyl)-9,10-dihydro-5H-phenant hro[9,10-e][1,2,4]triazolo[4,3-d][1,2,4]triazine 5a.