Heteroannulation of 6-polyfluoroalkyl-2-thiouracils

A multi-component double Mannich cyclocondensation of 6-polyfluoroalkyl-2-thiouracils with formalin and heterocyclic amines (2-aminopyridine, 2-aminopyrimidine, 4-aminoantipyrine) proceeded regiospecifically at the C=S and NH centers giving rise to 3-hetaryl-8-polyfluoroalkylpyrimido[2,1-b][1,3,5]thiadiazines. The regioisomeric structure of the products was established by X-ray crystallography, IR and NMR spectroscopy, GLC-MS spectrometry. 6-Trifluoromethyl-2-thiouracil and 8-polyfluoroalkylpyrimido[2,1-b]thiadiazines exhibited weak tuberculostatic activity.