Microwave assisted synthesis and antifungal studies of 5-amino thiadiazole substituted pyrimidine compounds

Simple synthetic methods of 5-(5-amino-1, 3, 4-thiadiazol-2yl)-3, 4-dihydro-6-methyl-4-phenylpyrimidin-2(1H)-thione (3f-j) are described. Compound 1 is converted to carbothiamide 2 by reacting compound 1 with thiosemicarbazide in catalytic amount of acetone is irradiated with help of domestic microwave oven (200W) for 2 minutes. Compound 2 is act as a key intermediate for the final compounds. The compound 2 is converted to corresponding thiadiazole 3 by treatment with conc. H₂SO₄ and NH₃. Structural elucidation is accomplished by IR, ¹H and ¹³CNMR, Elemental analysis and GC-Mass spectral data of the synthesized compounds. Few of these Pyrimidine derivatives have been evaluated for their possible antifungal activity. Most of the tested compounds show significant antifungal activity.