3-(6-Chloro-2-methyl-1H-indol-3-ylsulfanyl)-benzoic acid ethyl ester (0.250 g, 0.723 mmol) was combined with CuO (0.118 g, 1.48 mmol), potassium carbonate (0.130 g, 0.941 mmol) and 4-bromoisothiazole (0.250 g, 1.52 mmol) in pyridine (2 mL) and the reaction was heated to 145° C. overnight. After cooling the reaction was partitioned between H2O and DCM and the aqueous layer was extracted with DCM. The combined organics were dried over MgSO4 and concentrated then submitted to silica gel chromatography (0-20% EtOAc in hexanes) to yield the title compound.
