Monocyclic 1, 2, 3-triazines reacted with electron rich dienophiles to give pyridines and pyridazines. 4, 6-Disubstituted 1, 2, 3-triazine was denitrogenated to the azete intermediate, which afforded isomeric pyridines. 2, 5-Dihydrotriazines were oxidized by m-chloroperbenzoic acid to give 1, 2, 3-triazoles. Ring transformations of other triazine derivatives are also reported.
The synthesis of monosubstituted 1,2,3-triazinium salts 7-9 and their reactivity towards C-nucleophiles is described. The nucleophilic attack at 7-9 is regioselective at position 5, isolation of dihydroproducts was possible and an unusual ring contraction was observed.
N-Oxidation of substituted 1, 2, 3-triazines afforded the 1- and/or 2-oxides. The molecular structure of 4, 5, 6-triphenyl-1, 2, 3-triazine 2-oxide was studied crystallographically.
Alkyl substituted monocyclic 1,2,3-triazines and their 1-and 2-oxides have been synthesized; catalytic reduction (on Pd–C) of the triazines afforded their 2,5-dihydro compounds.