Reaction of Acetone Cyanohydrin with Thiosemicarbazide
We have established that when acetone cyanohydrin is heated with thiosemicarbazide in aqueous medium, 3-mercapto-6,6-dimethyl-1,2,4-triazin-5-one and 2-methyl-2-thiosemicarbazidopropanoic acid are formed. Cyclization of the latter in dioxane in the presence of H3BO3 leads to 2-amino-5,5-dimethyl-1,3,4-thiadiazin-6-one.