Naphtho cinnolines

R = H R = OMe) were obtained from the corresponding hydrazones in the former case the main product of the reaction was 1,2,3,4-tetrahydro-carbazol-l-one. Better yields were reported for the cyclization of 32 (R = Me R = H) and for the cyclohexane-1,2-dione mononaphthylhydra-zones, " the products from the last two being dehydrogenated to the fully aromatic naphtho[c] cinnolines. 

In practice, the azide decompositions are usually carried out in boiling toluene or xylene and give good yields of 3-alkyl-170,184,187 and 3-aryl-anthranils.185,188 Yields of 3-unsubstituted anthranils from o-azidoben-zaldehydes are generally much lower.170 The method has also been used to prepare 3-(j3-styryl)anthranils (106) from o-azidochalcones,189 3-methyl-naphtho[2,3-c]isoxazoles from 3-acetyl-2-azidonaphthalene,190 and 3-(2-pyridyl)anthranils from o-azidophenyl pyridyl ketones.191 This last reaction is of interest in that 2-(2-azido-3,5-dibromobenzoyl)pyridine in boiling toluene yields almost equal amounts of 5,7-dibromo-3-(2-pyridyl)anthranil (43%) and the zwitterionic pyrido[l,2-f>] cinnolin-6-ium 139 (41%). 

Condensed heterocyclic systems can also be obtained in this way when 2,2 -azonaphthalene is heated with aluminum chloride in methylene dichloride under reflux for 1 h, a 90% yield of benzo[/]naphtho[2,l-c]cinnoline is pro-... 

C1SH9CIN2O, 1-Chlorobenzia]phenazine-7N-oxide, 37B, 146 Ci6HioN2f Naphtho[2,1-c]cinnoline, 38B, 308... 

C20H2gBrNOg, cis-5,6,13,13a-Tetrahydro-3,9-dihydroxy-1,2,10-trimeth-oxy-8H-dibenzo[a,fIquinolizine hydrobromide monohydrate, 35B, 199 C21H12N2O3, 6-Methylbenzo[g]naphtho[1,2-c]-cinnoline-7,12,14-trione, 35B, 201... 

CjoNijNj Benzo[h]naphtho[l,2-c]cinnoline Benz[h]naphtho[l,2-c]cinnoIin 44.000/43.600 H 22/35... 

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