hydrogen; palladium/alumina in hydrogenchloride; methanol 6 h; Ambient temperature;

1: 1.) conc. sulfuric acid; 2.) nitric acid / 1.) 110 deg C, 4 h; 2.) r.t., 2 h 2: 77 percent / 3 h / 160 °C 3: 92 percent / H2 / Pd/Al2O3 / methanol; aq. HCl / 6 h / Ambient temperature View Scheme