1: potassium carbonate / dimethylformamide / 5 h 2: various solvent(s) / 4 h / Heating 3: H2 / PtO2 / acetic acid / 2206.5 Torr 4: HCl / ethanol / Heating 5: ethanol / 7 h / Heating 6: polyphosphoric acid / Heating 7: 1.) sodium hydride, 2.) HCl / 1.) DMF, RT, 24 h, 2.) reflux, 1 h 8: 0.1 M NaOH / methanol / 0.25 h / Heating View Scheme

1: potassium carbonate / dimethylformamide / 5 h 2: various solvent(s) / 4 h / Heating 3: H2 / PtO2 / acetic acid / 2206.5 Torr 4: HCl / ethanol / Heating View Scheme