An efficient, catalyst-free, regio- and diastereoselective approach for the synthesis
of novel 7-aryl-3-alkyl(aryl)-6-methyl-6,7-dihydro-5H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-6-ols has been developed via the reaction of 4-amino-[1,2,4]triazole-3-thiols
with nitroepoxides in methanol at room temperature. The products were simply dehydrated
in the presence of PTSA in ethanol at 70 °C to afford the corresponding 7-aryl-3-alkyl(aryl)-6-methyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines in 91–98% yields. In addition, treatment of the product with
acidic chloroform afforded the corresponding α-((4-amino-5-methyl-4H-1,2,4-triazol-3-yl)thio)-α-phenylpropan-2-one in quantitative yield.
Key words
nitroepoxide - 6,7-dihydro-5
H-[1,2,4]triazolo[3,4-
b][1,3,4]thiadiazin-6-ols - 7
H-[1,2,4]triazolo[3,4-
b][1,3,4]thiadiazines - diastereoselective - catalyst-free
