Aniline (I) was converted to the isothiocyanate (II) using thiophosgene in DMF, and then treated with cyanoacetamide and sulfur to afford thiazolothione (III). Subsequent reaction of (III) with acetic anhydride generated the pyrimidine (IV), which was chlorinated with refluxing POCl3 to give (V). Finally, condensation of (V) with diethylamine in boiling acetone furnished the target compound.