6-Polyfluoroalkylated 2-thiouracils in the synthesis of pyrimido[2,1-b][1,3,5]thiadiazines by the double Mannich reaction

► 6-Polyfluoroalkyl-2-thiouracils react with formaldehyde and primary amines to produce pyrimido[2,1-b][1,3,5]thiadiazines via the multicomponent double Mannich reaction. ► The use of ethylenediamine in these reactions results in the product of the bis-double Mannich cyclocondensation. ► 8-Polyfluoroalkyl-pyrimido[2,1-b]thiadiazines exhibit weak tuberculostatic activity.