disodium hydrogenphosphate; sodium amalgam in tetrahydrofuran; ethanol T=-20°C; 0.75 h;

nitric acid; sodium nitrite in water T=70 - 75°C; 1 h;

1: 91 percent / pyridine / CH2Cl2 / 1 h / Ambient temperature 2: 82 percent / dimethylsulfoxide / 1 h / Ambient temperature 3: 70.5 percent / zinc, acetic acid / dimethylformamide / 0.75 h / 0 °C 4: thionyl chloride / dimethylformamide / 4 h / 40 - 45 °C 5: 79 percent / pyridine / diethyl ether / 30 h / Heating 6: 1.) sodium hydride, 2.) 1,2-bis(diphenylphosphino)ethane / 2.) tetrakis(triphenylphosphine)palladium(0) / 1,) THF, 0 deg C, 30 min; room temperature, 15 min, 2.) reflux 7: 86 percent / tetramethylammonium acetate / hexamethylphosphoric acid triamide / 3 h / 95 - 100 °C 8: 94 percent / disodium hydrogen phosphate, 6percent sodium amalgam / ethanol; tetrahydrofuran / 0.75 h / -20 °C View Scheme

1: thionyl chloride / 1.) room temperature, 45 min, 2.) 45 deg C, 2 h 2: 91 percent / pyridine / CH2Cl2 / 1 h / Ambient temperature 3: 82 percent / dimethylsulfoxide / 1 h / Ambient temperature 4: 70.5 percent / zinc, acetic acid / dimethylformamide / 0.75 h / 0 °C 5: thionyl chloride / dimethylformamide / 4 h / 40 - 45 °C 6: 79 percent / pyridine / diethyl ether / 30 h / Heating 7: 1.) sodium hydride, 2.) 1,2-bis(diphenylphosphino)ethane / 2.) tetrakis(triphenylphosphine)palladium(0) / 1,) THF, 0 deg C, 30 min; room temperature, 15 min, 2.) reflux 8: 86 percent / tetramethylammonium acetate / hexamethylphosphoric acid triamide / 3 h / 95 - 100 °C 9: 94 percent / disodium hydrogen phosphate, 6percent sodium amalgam / ethanol; tetrahydrofuran / 0.75 h / -20 °C View Scheme

1: thionyl chloride / dimethylformamide / 4 h / 40 - 45 °C 2: 79 percent / pyridine / diethyl ether / 30 h / Heating 3: 1.) sodium hydride, 2.) 1,2-bis(diphenylphosphino)ethane / 2.) tetrakis(triphenylphosphine)palladium(0) / 1,) THF, 0 deg C, 30 min; room temperature, 15 min, 2.) reflux 4: 86 percent / tetramethylammonium acetate / hexamethylphosphoric acid triamide / 3 h / 95 - 100 °C 5: 94 percent / disodium hydrogen phosphate, 6percent sodium amalgam / ethanol; tetrahydrofuran / 0.75 h / -20 °C View Scheme

1: 79 percent / pyridine / diethyl ether / 30 h / Heating 2: 1.) sodium hydride, 2.) 1,2-bis(diphenylphosphino)ethane / 2.) tetrakis(triphenylphosphine)palladium(0) / 1,) THF, 0 deg C, 30 min; room temperature, 15 min, 2.) reflux 3: 86 percent / tetramethylammonium acetate / hexamethylphosphoric acid triamide / 3 h / 95 - 100 °C 4: 94 percent / disodium hydrogen phosphate, 6percent sodium amalgam / ethanol; tetrahydrofuran / 0.75 h / -20 °C View Scheme

1: 88 percent / diisobutylaluminium hydride / toluene; hexane / 0.5 h / 0 °C 2: 91 percent / pyridine / CH2Cl2 / 0.5 h / 0 °C 3: 95 percent / perchloric acid / tetrahydrofuran; H2O / 8 h / Ambient temperature 4: 79 percent / pyridine / diethyl ether / 30 h / Heating 5: 1.) sodium hydride, 2.) 1,2-bis(diphenylphosphino)ethane / 2.) tetrakis(triphenylphosphine)palladium(0) / 1,) THF, 0 deg C, 30 min; room temperature, 15 min, 2.) reflux 6: 86 percent / tetramethylammonium acetate / hexamethylphosphoric acid triamide / 3 h / 95 - 100 °C 7: 94 percent / disodium hydrogen phosphate, 6percent sodium amalgam / ethanol; tetrahydrofuran / 0.75 h / -20 °C View Scheme

1: 91 percent / pyridine / CH2Cl2 / 0.5 h / 0 °C 2: 95 percent / perchloric acid / tetrahydrofuran; H2O / 8 h / Ambient temperature 3: 79 percent / pyridine / diethyl ether / 30 h / Heating 4: 1.) sodium hydride, 2.) 1,2-bis(diphenylphosphino)ethane / 2.) tetrakis(triphenylphosphine)palladium(0) / 1,) THF, 0 deg C, 30 min; room temperature, 15 min, 2.) reflux 5: 86 percent / tetramethylammonium acetate / hexamethylphosphoric acid triamide / 3 h / 95 - 100 °C 6: 94 percent / disodium hydrogen phosphate, 6percent sodium amalgam / ethanol; tetrahydrofuran / 0.75 h / -20 °C View Scheme

1: 82 percent / dimethylsulfoxide / 1 h / Ambient temperature 2: 70.5 percent / zinc, acetic acid / dimethylformamide / 0.75 h / 0 °C 3: thionyl chloride / dimethylformamide / 4 h / 40 - 45 °C 4: 79 percent / pyridine / diethyl ether / 30 h / Heating 5: 1.) sodium hydride, 2.) 1,2-bis(diphenylphosphino)ethane / 2.) tetrakis(triphenylphosphine)palladium(0) / 1,) THF, 0 deg C, 30 min; room temperature, 15 min, 2.) reflux 6: 86 percent / tetramethylammonium acetate / hexamethylphosphoric acid triamide / 3 h / 95 - 100 °C 7: 94 percent / disodium hydrogen phosphate, 6percent sodium amalgam / ethanol; tetrahydrofuran / 0.75 h / -20 °C View Scheme

1: 95 percent / perchloric acid / tetrahydrofuran; H2O / 8 h / Ambient temperature 2: 79 percent / pyridine / diethyl ether / 30 h / Heating 3: 1.) sodium hydride, 2.) 1,2-bis(diphenylphosphino)ethane / 2.) tetrakis(triphenylphosphine)palladium(0) / 1,) THF, 0 deg C, 30 min; room temperature, 15 min, 2.) reflux 4: 86 percent / tetramethylammonium acetate / hexamethylphosphoric acid triamide / 3 h / 95 - 100 °C 5: 94 percent / disodium hydrogen phosphate, 6percent sodium amalgam / ethanol; tetrahydrofuran / 0.75 h / -20 °C View Scheme