Potential Anticancer Agents. XIII. Reaction of 3, 6-Dimethylpyridazine 1-Oxide and Methylpyridazine 1-Oxides with Benzaldehyde

The nucleophilic activity of methyl group in 3, 6-dimethylpyridazine 1-oxide (I) and monomethylpyridazine 1-oxides (II) with benzaldehyde was studied. Their corresponding (β-hydroxyphenethyl) pyridazine 1-oxides and styryl compounds were gained. From the results, it may be deduced as follows. (i) The reactivity of 3-and 6-methyl groups in I were almost same, different from the cases of 3, 6-dichloropyridazine 1-oxide. (ii) 4- and 6-methyl groups in II were similarly reactive, but 5-methyl was more active, and 3-methyl less active than fore-mentioned two methyl groups. These styryl compounds that were produced respectively, were catalytically hydrogenated with Pd-C to corresponding phenethylpyridazine 1-oxides.