The oxidative cyclisation of a range of benzothieno[2,3-d]pyrimidine hydrazones (7a-e) to the 1,2,4-triazolo [4,3-c]pyrimidines (8a-e) catalysed by lithium iodide or to the 1,2,4-triazolo[1,5-c]pyrimidines (10a-e) with sodium carbonate is presented. A complementary synthesis of the 1,2,4-triazolo[1,5-c]pyrimidines (10a-e) starting from the amino imine 11 is also reported. The effect of these compounds on Shiga toxin (STx) trafficking in HeLa cells and comparison to the previously reported Exo2 is also detailed