Unexpected reactivity of 3-ethylsulfonyl-1,2,4-triazines with B12H11SH⌉2–: first examples of the synthesis of boron-centered as-triazines and thioesters of ethyl sulfinic acid

The reaction of 3-ethylsulfonyl-5-methylamino-6-methylcarboxamido-1,2,4-triazine 1 with B₁₂H₁₁SH⌉^2– yields the boron-containing derivatives of 1,2,4-triazine 3. The interaction of 5,7-dimethyl-5,6,7,8-tetrahydropyrimido[4,5-e][1,2,4]triazine-6,8-dione 2 with mercaptoborane B₁₂H₁₁SH⌉^2– gives boron-containing thiosulfinate 4 and bis(heteryl) ether 5.