pyridine in acetonitrile T=45°C; 16 h;

1: 97 percent / H2 / 5 percent Pd/C / methanol / 5 h / 20 °C / 3750.3 Torr 2: 86 percent / conc. aq. HCl; 35 percent aq. H2O2 / 0.5 h / 20 °C 3: 75 percent / pyridine / acetonitrile / 16 h / 45 °C View Scheme

1: 86 percent / conc. aq. HCl; 35 percent aq. H2O2 / 0.5 h / 20 °C 2: 75 percent / pyridine / acetonitrile / 16 h / 45 °C View Scheme

in dimethyl sulfoxide T=120°C; 12 h;