To a suspension of 2,2′-bis(diphenylphosphino)-1,1′binaphthyl (3.1 mg), tris(dibenzylideneacetone)dipalladium (0) (1.5 mg) and sodium-tert.-butylate (19 mg) in toluene (15 ml) were added 6-[2-(4-bromo-2-chloro-phenyl)-1-hydroxy-1-trifluoromethyl-propyl]-4-methyl-4H-benzo[1,4]oxazin-3-one (Example 22, step 3, 80 mg) and ethyl piperidine-4-carboxylate (29 mg). The mixture was stirred at room temperature overnight. 2,2′-Bis(diphenylphosphino)-1,1′binaphthyl (3.1 mg), ethyl piperidine-4-carboxylate (29 mg) and tris(dibenzylideneacetone)dipalladium (0) (1.5 mg) were added and the mixture was stirred at 80° C. for 4 h. After cooling to room temperature, the mixture was diluted with EtOAc. The organic phase was washed with water, dried (MgSO4), filtered and concentrated to dryness. The product was purified by chromatography (SiO2, cyclohexane/EtOAc 1:0=>4:1) to give the title compound (3 mg) as light yellow oil. MS (m/e)=555.3 [M+H+].
