A solution of ethyl 3-(bromomethyl)-5-[4-(trifluoromethyl)phenyl]thiophene-2-carboxylate (intermediate 43, 0.100 g) and benzyl mercaptan (0.30 g) in acetonitrile (10 ml) was treated with potassium carbonate (0.46 g) and the mixture stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and water the organic layer as collected, dried over magnesium sulfate and concentrated. The residue was purified by SPE (Si cartridge) eluting initially with cyclohexane:chloroform (5:1) and then cyclohexane:chloroform (1:3) to give the title compound as a colourless oil.
