A mixture of 4-isopropylbenzenethiol (2.288 g), 3-bromopyridin-2-amine (2.0 g), (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphine) (0.669 g), tris(dibenzylideneacetone)dipalladium(0) (0.529 g) and DIEA (7.47 mL) in toluene (57.8 mL) was stirred overnight under a nitrogen atmosphere at 120° C. The reaction mixture was added to water, filtered through celite, and the filtrate was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give the title compound (2508 mg) as a pale-yellow solid.
