To 2-amino-4-(1-(2-fluoro-4-biphenylyl)ethyl) thiazole (0.50 g, 1.68 mmol) in acetone (10 ml) were added phenylisothiocyanate (0.25 g, 1.85 mmol) in acetone (5 ml) and sodium hydrogen carbonate (0.30 g). After the mixture was refluxed for 10 h, phenyisothiocyanate (0.50 g, 3.70 mmol) was added to the mixture, and then the mixture was refluxed for 2 h. The mixture was evaporated under reduced pressure to a residue, which was chromatographed and recrystallized to afford N-phenyl-N'-(4-(1-(2-fluoro-4-biphenylyl)ethyl)thiazol-2-yl)thiourea (0.115 g, 16% yield) as crystalline material: mp 176.5°-177.0° C.
