Abstract Reaction of nitrous acid with 4-substituted and 4, 6-substituted 5-aminopyrimidines Ia-In produces 4-substituted and 4, 5-disubstituted 1, 2, 3-triazoles IIa-IIv, resp. Under similar conditions, 2, 5-diaminopyrimidines XIIa-XIId give N (7)-oxides of 2-amino-4- aralkylthiopyrimido [5, 4-d]-1, 2, 3-triazines XIIIa-XIIId, and 5-amino-4-chloropyrimidines In and X give 2-diazocyanoacetamides XIa and XIb resp. Also described are syntheses of 5- ...
