3 4 5 6-tetrahydro-2-pyrimidinethiol July 8, 2019 16 32 64 128 3 4 5 6 tetrahydro 2 pyrimidinethiol 3 6-di-2-pyridyl-1 2 4 5-tetrazine 3 4-dihydro- 4 4 6-trimethyl-2(1h)-pyrimidone 3 6-di(pyridin-4-yl)-1 2 4 5-tetrazine 3 6-di(pyridin-2-yl)-1 2 4 5-tetrazine
