1: 72 percent / K2CO3 / dimethylformamide / 24 h / Ambient temperature 2: 81 percent / K2CO3 / dimethylformamide / 24 h / 20 °C 3: KOH / ethanol; H2O / 0.67 h / Heating 4: copper bronze, quinoline / 185 °C 5: 1.) C-200 (BaCO3*0.8H2O), 2.) H2O / 1.) THF, 2.) THF, reflux, 1 h 6: KOH / ethanol; H2O / 0.67 h / Heating 7: 42 percent / polyphosphoric acid silyl ester (PPSE) / 24 h / 100 °C View Scheme

1: 81 percent / K2CO3 / dimethylformamide / 24 h / 20 °C 2: KOH / ethanol; H2O / 0.67 h / Heating 3: copper bronze, quinoline / 185 °C 4: 1.) C-200 (BaCO3*0.8H2O), 2.) H2O / 1.) THF, 2.) THF, reflux, 1 h 5: KOH / ethanol; H2O / 0.67 h / Heating 6: 42 percent / polyphosphoric acid silyl ester (PPSE) / 24 h / 100 °C View Scheme