1: 86 percent / diethyl ether; methanol; CHCl3 / 0.17 h / 0 °C 2: 86 percent / AcOH, polyphosphoric acid / acetonitrile / 12 h / Ambient temperature 3: 77 percent / NH2OH*HCl, NaOAc / ethanol / 1 h / Heating 4: 51 percent / xylene / 24 h / Heating 5: 95 percent / 10percent aqueous NaOH / ethanol / 1 h / Heating 6: 98 percent / diphenylphosphoryl azide (DPPA), triethylamine / 0.5 h / 80 °C 7: 81 percent / AcOH / H2O / 1 h / 80 °C View Scheme

1: 86 percent / diethyl ether; methanol; CHCl3 / 0.17 h / 0 °C 2: 86 percent / AcOH, polyphosphoric acid / acetonitrile / 12 h / Ambient temperature 3: 77 percent / NH2OH*HCl, NaOAc / ethanol / 1 h / Heating 4: 51 percent / xylene / 24 h / Heating 5: 95 percent / 10percent aqueous NaOH / ethanol / 1 h / Heating View Scheme