1: 81 percent / P2O5, 85percent aq H3PO4 / toluene / 2 h / 100 °C / Heating 2: 92 percent / NaBH4 / ethanol / 4 h / Heating 3: 94 percent / HCl,CaCl2 / CCl4 / 1.5 h / Ambient temperature 4: 72 percent / NaH / benzene / 1. 3 h reflux; 2. room temp., overnight 5: 79 percent / KOH / ethanol; H2O / 6 h / Heating 6: 95 percent / Piperidine / pyridine / 2.5 h / Heating 7: 88 percent / SOCl2 / benzene / 1. 60-70 deg C, 2.5 h; 2. 0.5 h reflux 8: 99 percent / NH3 / benzene / Ambient temperature View Scheme

1: 81 percent / P2O5, 85percent aq H3PO4 / toluene / 2 h / 100 °C / Heating 2: 92 percent / NaBH4 / ethanol / 4 h / Heating 3: 94 percent / HCl,CaCl2 / CCl4 / 1.5 h / Ambient temperature 4: 72 percent / NaH / benzene / 1. 3 h reflux; 2. room temp., overnight 5: 79 percent / KOH / ethanol; H2O / 6 h / Heating 6: 95 percent / Piperidine / pyridine / 2.5 h / Heating View Scheme