2 4 6 8 tetrachloropyrimido 5 4 d pyrimidine July 8, 2019 16 32 64 128 2 4 5 trioxin 2 4 5 6-tetraaminopyrimidine 4 6-dichloro-2-(propylthio)pyrimidin-5-amine 4'-(4 '-pyridyl)- 2 2'-6' 2''- terpyridine
