To a solution of methyl 2-ethylthio-4-methylthieno[3,4-d]imidazole-6-carboxylate (5.7 g) in DMF (30 ml) was added sodium hydride (60% oil, 0.98 g) under ice-cooling. After stirring the reaction mixture for 20 minutes, to the mixture was added dropwise a solution of (2'-cyanobiphenyl-4-yl)methyl bromide (7.25 g) in DMF (20 ml), followed by stirring for one hour at room temperature. To the reaction mixture was added water, which was extracted with ethyl acetate. The extract was washed with water and dried, then the solvent was evaporated in vacuo. The residue was purified by silica gel column chromatography to give crystals. Recrystallization from ethyl acetate - hexane afforded pale yellow prisms (7.6 g, 77%), m.p. 149°-151° C.
