N-Methylation of 4(7)-nitrobenzotriazole (I) afforded a mixture of three isomers; one of them, 4-nitro-2-methylbenzotriazole (II) could easily be isolated. Catalytical hydrogenation of II led to the corresponding amine which in turn, afforded products of nucleophilic substitution IVa-IVi on reaction with alkoxymethylene derivatives IIIa-IIIi. Thermal cyclocondensation of IVi yielded 7-ethoxycarbonyl-6,9-dihydro-6-oxo-2-methyl-2H-triazolo[4,5-h]quinoline (V). The structure of all products was deduced from the IR, UV, 1H and 13C NMR spectral data.
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Milata et al. (1990) studied this question.