The scope of functionalization of 1,2,4-triazines can be considerably extended via successive nucleophilic substitution of hydrogen (S-N(H)) and ipso-substitution. A convenient procedure has been developed for direct cyanation of 1,2,4-triazine 4-oxides with acetone cyanohydrin in the presence of triethylamine. The cyano group in the resulting 5-cyano-1,2,4-triazines is readily replaced by reactions with various aliphatic alcohols and amines.
The scope of functionalization of 1,2,4-triazines can be considerably extended via successive nucleophilic substitution of hydrogen (S-N(H)) and ipso-substitution. A convenient procedure has been developed for direct cyanation of 1,2,4-triazine 4-oxides with acetone cyanohydrin in the presence of triethylamine. The cyano group in the resulting 5-cyano-1,2,4-triazines is readily replaced by reactions with various aliphatic alcohols and amines.