in pyridine 0.5 h; Ambient temperature;

1: 77 percent / Cu, K2CO3 / dimethylformamide / 18 h / Heating 2: 1.) 50percent polyphosphoric acid / 1.) 130 deg C, 4 h, 2.) reflux, 18 h 3: 71 percent / 56percent HI / 3 h / Heating 4: 86 percent / pyridine / 1 h / Ambient temperature View Scheme

1: 77 percent / Cu, K2CO3 / dimethylformamide / 18 h / Heating 2: 1.) 50percent polyphosphoric acid / 1.) 130 deg C, 4 h, 2.) reflux, 18 h 3: 71 percent / 56percent HI / 3 h / Heating 4: 86 percent / pyridine / 1 h / Ambient temperature View Scheme

1: 64 percent / Zn, acetic acid / 4 h / Heating 2: 77 percent / Cu, K2CO3 / dimethylformamide / 18 h / Heating 3: 1.) 50percent polyphosphoric acid / 1.) 130 deg C, 4 h, 2.) reflux, 18 h 4: 71 percent / 56percent HI / 3 h / Heating 5: 86 percent / pyridine / 1 h / Ambient temperature View Scheme

1: 1.) 50percent polyphosphoric acid / 1.) 130 deg C, 4 h, 2.) reflux, 18 h 2: 71 percent / 56percent HI / 3 h / Heating 3: 86 percent / pyridine / 1 h / Ambient temperature View Scheme

1: 71 percent / 56percent HI / 3 h / Heating 2: 86 percent / pyridine / 1 h / Ambient temperature View Scheme

1: 64 percent / 20percent aq. acetic acid / 72 h / 70 - 80 °C 2: 92 percent / 5 N aq. KOH / ethanol / 0.5 h / Heating View Scheme