T=200°C; 1 h;

1: NaBH4, NaHCO3 / ethanol; H2O / 5 °C 2: polyphosphoric acid / 180 °C 3: H2 / Pd-C / ethanol / 45 °C / 760 Torr View Scheme

1: 86 percent / CuCl2*2H2O, NaBH4 / ethanol / 0.75 h / 0 °C 2: 44 percent / 37percent aq. HCl / 5 h / 60 °C 3: 94 percent / 2N aq. HCl, H2 / 5percent Pd/C / methanol / 4 h / 60 °C / 3420 Torr 4: 70 percent / triethylamine / 1,2-dimethoxy-ethane / 20 h / Ambient temperature View Scheme