1: thionyl chloride / 1 h / 50 °C 2: 1.) triethylamine; 2.) 20percent HCl / 1.) chloroform, 35 deg C, 5 h; 2.) chloroform, reflux, 5 h 3: sodium hydroxide / ethanol / 1 h / Heating 4: 1.) hydrazine hydrate; 2.) potassium hydroxide / 1.) triethanolamine, 130 deg C; reflux, 4 h; 2.) triethanolamine, 200 deg C, 9 h 5: thionyl chloride / 1 h / 50 °C 6: 1.) triethylamine; 2.) 20percent HCl / 1.) chloroform, 35 deg C, 5 h; 2.) chloroform, reflux, 5 h 7: sodium hydroxide / ethanol / 1 h / Heating 8: 1.) hydrazine hydrate; 2.) potassium hydroxide / 1.) triethanolamine, 130 deg C; reflux, 4 h; 2.) triethanolamine, 200 deg C, 9 h 9: thionyl chloride / 1 h / 50 °C View Scheme

1: thionyl chloride / 1 h / 50 °C 2: 1.) triethylamine; 2.) 20percent HCl / 1.) chloroform, 35 deg C, 5 h; 2.) chloroform, reflux, 5 h 3: sodium hydroxide / ethanol / 1 h / Heating 4: 1.) hydrazine hydrate; 2.) potassium hydroxide / 1.) triethanolamine, 130 deg C; reflux, 4 h; 2.) triethanolamine, 200 deg C, 9 h 5: thionyl chloride / 1 h / 50 °C View Scheme

1: sodium hydroxide / ethanol / 1 h / Heating 2: 1.) hydrazine hydrate; 2.) potassium hydroxide / 1.) triethanolamine, 130 deg C; reflux, 4 h; 2.) triethanolamine, 200 deg C, 9 h 3: thionyl chloride / 1 h / 50 °C 4: 1.) triethylamine; 2.) 20percent HCl / 1.) chloroform, 35 deg C, 5 h; 2.) chloroform, reflux, 5 h 5: sodium hydroxide / ethanol / 1 h / Heating 6: 1.) hydrazine hydrate; 2.) potassium hydroxide / 1.) triethanolamine, 130 deg C; reflux, 4 h; 2.) triethanolamine, 200 deg C, 9 h 7: thionyl chloride / 1 h / 50 °C View Scheme

1: 1.) triethylamine; 2.) 20percent HCl / 1.) chloroform, 35 deg C, 5 h; 2.) chloroform, reflux, 5 h 2: sodium hydroxide / ethanol / 1 h / Heating 3: 1.) hydrazine hydrate; 2.) potassium hydroxide / 1.) triethanolamine, 130 deg C; reflux, 4 h; 2.) triethanolamine, 200 deg C, 9 h 4: thionyl chloride / 1 h / 50 °C 5: 1.) triethylamine; 2.) 20percent HCl / 1.) chloroform, 35 deg C, 5 h; 2.) chloroform, reflux, 5 h 6: sodium hydroxide / ethanol / 1 h / Heating 7: 1.) hydrazine hydrate; 2.) potassium hydroxide / 1.) triethanolamine, 130 deg C; reflux, 4 h; 2.) triethanolamine, 200 deg C, 9 h 8: thionyl chloride / 1 h / 50 °C View Scheme

1: 69 percent / PDC / dimethylformamide 2: Cu(OAc)2 / pyridine / 0.17 h / Heating 3: H2 / 10 percent Pd/C / CHCl3 / 20 °C 4: aq. NaOH / tetrahydrofuran / 20 °C 5: oxalyl chloride / CH2Cl2 / 12 h / 20 °C View Scheme

1: Cu(OAc)2 / pyridine / 0.17 h / Heating 2: H2 / 10 percent Pd/C / CHCl3 / 20 °C 3: aq. NaOH / tetrahydrofuran / 20 °C 4: oxalyl chloride / CH2Cl2 / 12 h / 20 °C View Scheme

1: 100 percent / p-TSA / methanol / 20 °C 2: 68 percent / NaH; 1,3-diaminopropane / 70 °C 3: 69 percent / PDC / dimethylformamide 4: Cu(OAc)2 / pyridine / 0.17 h / Heating 5: H2 / 10 percent Pd/C / CHCl3 / 20 °C 6: aq. NaOH / tetrahydrofuran / 20 °C 7: oxalyl chloride / CH2Cl2 / 12 h / 20 °C View Scheme