1: 90 percent / DVP-Fe, conc. HCl / aq. ethanol; H2O / Heating 2: conc. H3PO4 / xylene / 140 °C 3: 90 percent / xylene / Heating 4: dimethylformamide / 8 h / Ambient temperature View Scheme

1: K2CO3 / dimethylformamide / 140 °C 2: 90 percent / DVP-Fe, conc. HCl / aq. ethanol; H2O / Heating 3: conc. H3PO4 / xylene / 140 °C 4: 90 percent / xylene / Heating 5: dimethylformamide / 8 h / Ambient temperature View Scheme

1: K2CO3 / dimethylformamide / 140 °C 2: 90 percent / DVP-Fe, conc. HCl / aq. ethanol; H2O / Heating 3: conc. H3PO4 / xylene / 140 °C 4: 90 percent / xylene / Heating 5: dimethylformamide / 8 h / Ambient temperature View Scheme

1: conc. H3PO4 / xylene / 140 °C 2: 90 percent / xylene / Heating 3: dimethylformamide / 8 h / Ambient temperature View Scheme

1: 90 percent / xylene / Heating 2: dimethylformamide / 8 h / Ambient temperature View Scheme

in N,N-dimethyl-formamide 8 h; Ambient temperature;