caesium carbonate in DMF (N,N-dimethyl-formamide) T=20°C; 24 h;

1: With triethylamine; (1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride in 1,4-dioxane T=80°C; 18 h; 2: ethyl (4-bromophenoxy)acetate; 4,4,5,5-tetramethyl-[1,3,2]dioxaborolane in 1,4-dioxane T=80°C; 52 h;