1: 80 percent / Cu / dimethylformamide / 2 h / Heating 2: 88 percent / KOH / aq. ethanol View Scheme

Multi-step reaction with 3 steps 1: KOH / aq. ethanol2: 85 percent / benzene; pyridine / r.t.; ref., 3 h3: 93 percent / benzene; pyridine / r.t.,; ref., 3 h  

Multi-step reaction with 4 steps 1: 44 percent / Cu / dimethylformamide / 2 h / Heating2: KOH / aq. ethanol3: 85 percent / benzene; pyridine / r.t.; ref., 3 h4: 93 percent / benzene; pyridine / r.t.,; ref., 3 h  

Multi-step reaction with 4 steps 1: 80 percent / Cu / dimethylformamide / 2 h / Heating2: 88 percent / KOH / aq. ethanol3: 81 percent / benzene; pyridine / r.t.; ref., 3 h4: 86 percent / benzene; pyridine / r.t.,; ref., 3 h  

With  copper in  N,N-dimethyl-formamide 2 h;  Heating;