Aromatic azapentalenes. V. 1,1'-and 1,2'-Dibenzo-triazoles and their conversion to dibenzotetraazapentalenes

Abstract

The syntheses, physical properties, and structural assignments for 1,l '-bibenzotriazole (4a) and 1,2'bibenzotriazole (8) are described. Both 4a and 8 lose nitrogen on heating to give dibenzo-1,3a,4,6a-tetraazapentalene (1) and dibenzo-l,3a,6,6a-tetraazapentalene (2), respectively.

Benzotriazole as a structural component in chelating and bridging heterocyclic ligands; ruthenium, palladium, copper and silver complexes

“…1,1Ј-Bibenzotriazole (2) was prepared by cyclisation of a 2,2Ј-azobenzene bisdiazonium salt, as previously reported. 11 The other ligands (3-6) were prepared by nucleophilic substitution reactions of benzotriazole with diiodomethane, 12 2-bromopyridine, 13 2chloromethylpyridine 14 and 1-chloroisoquinoline, respectively. In order to explore the chemistry of these ligands, we selected four metal ions as representative subjects for coordination.…”

Solid state conformations of symmetrical aromatic biheterocycles: an X-ray crystallographic investigation

“…20,21 X-Ray quality crystals were obtained by recrystallisation from chloroform and dioxane, respectively. 1,1 -Bibenzotriazole (12) was obtained from 2,2diaminoazobenzene by diazotisation followed by reductive cyclisation, as described by Harder et al, 22 and was recrystallised from ethyl acetate.…”

Nucleophilic substitution in quaternary salts of NN′-linked biazoles and related systems.

“…Synthesk-Compounds (1)- (7) were prepared in a few steps from the corresponding N-aminoazoles, i,e., 1 -aminobenz- ' l and 2,5-diethoxytetrahydrof ~r a n , ~" respectively. For the cyclization of the 2,6-dimethyl-4pyridone ring [compounds (3) and (7)] we followed the method described by Katritzky for 2,6-dimethyl-1-( 1,2,4-triazol-4-~1)-4pyridone,' using dehydroacetic acid (8) and the corresponding 1-aminoazole. Although no problems were encountered under standard experimental conditions (reflux in pyridine) in the case of pyrazole, the reaction failed to give the expected compound (9) when applied to 1-aminobenzimidazole, the intermediate…”