Synthesis of 6-cyano-7- [P-methoxyphenyl] -5-oxo-2- [polyhydroxyalkyl] -8H- [1,2,4] triazolopyrimidines

A series of the hydrazones III, IX and XII were prepared by the reaction of 5-cyano-2-hydrazino-6-[p-methoxyphenyl]- 3,4-dihydropyrimidin-4-one [I] with the respective sugar. Acetylation of the products with acetic anhydride in pyridine was studied. Cyclodehydrogenation of III gave 6-cyano-7-[p- methoxyphenyl]-5-oxo-2-[polyhydroxyalkyl]-8H-[1,2,4] triazolo [1,5-a] pyrimidine [V]. Periodate oxidation of IIIa gave 5-cyano-6-[p- methoxyphenyl]-2-[2-oxoethylidenehydrazino]-3,4-dihydropyrimidin-4- one [VII]