A mixture of 4-(2,2,2-trifluoroethoxy)benzoic acid (0.30 g, 1.35 mmol) and thionyl chloride (0.32 g, 2.72 mmol) in chloroform (5 ml) was heated under reflux for 4 h. The reaction mixture was cooled to room temperature and the excess reagent and solvent was removed under reduced pressure to give the crude acid chloride. The amide was prepared as described in the Amide Coupling section using the crude acid chloride and 2-(4-aminophenyl)-6-methoxybenzothiazole (0.34 g, 1.35 mmol) in dry pyridine (15 ml) to give the title compound (0.56 g, 91%) as a pale yellow solid after work-up.
