1: 2.2 g / H2 / 5percent Pd/CaCO3 / ethanol / 1 h / 25 °C / 103.4 Torr 2: 1.5 g / diethyl ether / 15 h / -50 - -30 °C 3: 560 mg / NH2OH*HCl, pyridine / 96 h / 25 °C 4: 59 mg / POCl3, pyridine / 3 h / -15 °C View Scheme