1: Et3N / pyridine / 0 - 3 °C 2: aq. NH3 / H2O / 20 h / Ambient temperature; pH 8-9 3: 48 percent / H2, Dowex anion-exchange resin, KHCO3 / Pd black / propan-2-ol; H2O / 70 h / 70 °C / 19000 - 22800 Torr View Scheme