1: 75 percent / 4-dimethylaminopyridine / pyridine / 1 h / 50 - 60 °C 2: 97 percent / 10percent Pd-C / ethanol / Ambient temperature 3: 52 percent / Ag2O, drierite, quinoline 4: 80 percent / Ba(OH)2 / H2O / 24 h / Ambient temperature 5: 39 percent / SO3-pyridine-complex / dimethylformamide / 0.08 h / 40 °C View Scheme