potassium hydroxide; water in 1,2-diethyl benzene T=175°C; 5.5 h;

potassium carbonate; copper(l) iodide in 1,2-diethyl benzene T=200°C; 18 h;

(nBu4N+)2(Cu2I4)2−; trans-N,N'-dimethyl-1,2-cyclohexanediamine bis-(methanesulfonic acid); caesium carbonate in 1,4-dioxane T=130°C; 24 h; Inert atmosphere; Overall yield = 70 percent; Overall yield = 402 mg;