7-Hydroxy-5-methyl-1,3,4-triazindolizine is used as an intermediate for the drug oxazolidine, and can also be used as an anti-fogging agent for negative films. 7-Hydroxy-5-methyl[1,2,4]tris Chemicalbook azolo[1,5-a]pyrimidine can be used as a reactant to prepare triazolopyrimidine-based dihydroorotate dehydrogenase inhibitors , has potent and selective activity against the malaria parasite Plasmodium falciparum.