1: 29 percent / H2O / 5 h / 150 °C 2: 58 percent / diethyl azodicarboxylate, Ph3P / tetrahydrofuran / 18 h / Ambient temperature 3: 96 percent / 2N aq. HCl / methanol / 2 h / Heating View Scheme

1: 29 percent / H2O / 5 h / 150 °C 2: 58 percent / diethyl azodicarboxylate, Ph3P / tetrahydrofuran / 18 h / Ambient temperature 3: 96 percent / 2N aq. HCl / methanol / 2 h / Heating 4: SOCl2 / CHCl3 / 1 h / Heating 5: dimethylformamide / 1 h / Ambient temperature 6: 65 percent / piperidine / ethanol / 18 h / Heating 7: 56 percent / NaBH4, 1.0N aq. NaOH, CoCl2*6H2O, 2,2'-dipyridyl / dimethylformamide; tetrahydrofuran / 18 h / Ambient temperature 8: 72 percent / 4N aq. HCl / 18 h / Heating View Scheme