1: CsF / ethanol / 87 h / Ambient temperature 2: 65 percent / KOH / ethanol; H2O / 5 h / Ambient temperature 3: 68 percent / Et3N, diphenoxyphosphorylazid / 24 h / Heating 4: 81 percent / 37percent HCl / ethanol; H2O / 2 h / Heating 5: 72 percent / NaNO2 / aq. HCl; H2O / 1 h / 90 - 95 °C View Scheme