A solution of tris(dibenzylideneacetone)dipalladium (0) (0.18 g), 1,1′-bis(diphenylphosphino)ferrocene (0.10 g), sodium tert-butoxide (0.6 g) in 1,4-dioxane (10 ml) was stirred under an atmosphere of argon for 10 minutes. 1,1-Dimethylethyl 4-{[({4-[(difluoromethyl)oxy]-2-iodophenyl}amino)carbonyl]amino}-1-piperidinecarboxylate (D52, 1.3 g) was added and the mixture was heated to 90° C. The mixture was stirred at this temperature overnight. The mixture was poured into dichloromethane which was washed with water and brine. The solvent was removed and the residue was chromatographed on silica gel eluted with ethyl acetate/hexane 0-50% to give the title compound as a off-white solid. (0.54 g).
