SYNTHESIS OF NEW V-TRIAZOLOPYRIMIDINIUM SALTS

New v-triazolo[1,5-a]- and v-triazolo[1,5-c]pyrimidinium salts 12a-e, 13a-c have been synthesized via oxidation (i.e. cyclodehydrogenation) of the appropriate pyrimidyl ketone arylhydrazones 3a-e, 6a-c using TB B (2,4,4,6-tetrabromocyclohexa-2,5-dien-1-one) as the reagent. The ary lhydrazones were obtained by standard reactions; the Grignard reaction of 2-cyano- and 4-cyanopyrimidine 1a,b, 4a-c gave 2-pyrimidyl- and 4- pyrimidyl ketones 2a-e, 5a-c, which reacted with arylhydrazines to yie ld the desired ketone arylhydrazones 3a-e, 6a-c.