potassium carbonate in N,N-dimethyl-formamide 1 h; Ambient temperature;

1: 95 percent / K2CO3 / dimethylformamide / 1 h / Ambient temperature 2: 1) NaH / 1) DMF, 10 min, r.t., 2) DMF, 30 min, cooling 3: 100 percent / P2S5 / toluene / 2 h / Heating 4: 67 percent / 2 N NaOH / dioxane; methanol / 0.5 h View Scheme