in pyridine T=100°C; 2 h;

pyridine

1: 0 °C 2: triethylamine, ethyl chloroformate / CHCl3 / 3.5 h / Ambient temperature 3: 1.) sodium hydride / 1.) THF, RT, 1 h, 2.) THF, RT, 1 h 4: dimethylformamide / 2 h / Ambient temperature 5: diphenyl ether / 0.2 h / 250 °C 6: 84 percent / trifluoromethanesulfonic acid, trifluoroacetic acid, anisole / 2 h / Ambient temperature 7: 1.) sodium / 1.) ethanol, 0 de C,1,5 h, 2.) ethanol, RT, 3,5 h 8: 72 percent / conc. sulfuric acid / 1 h / 0 °C 9: 88 percent / sodium hydroxide, water / ethanol / 2 h / Heating 10: 13 percent / pyridine / 55 h / Heating View Scheme

1: 1.) sodium hydride / 1.) THF, RT, 1 h, 2.) THF, RT, 1 h 2: dimethylformamide / 2 h / Ambient temperature 3: diphenyl ether / 0.2 h / 250 °C 4: 84 percent / trifluoromethanesulfonic acid, trifluoroacetic acid, anisole / 2 h / Ambient temperature 5: 1.) sodium / 1.) ethanol, 0 de C,1,5 h, 2.) ethanol, RT, 3,5 h 6: 72 percent / conc. sulfuric acid / 1 h / 0 °C 7: 88 percent / sodium hydroxide, water / ethanol / 2 h / Heating 8: 13 percent / pyridine / 55 h / Heating View Scheme

1: 1.) sodium hydride / 1.) THF, RT, 1 h, 2.) THF, RT, 1 h 2: 67 percent / dimethylformamide / 2 h / Ambient temperature 3: diphenyl ether / 0.2 h / 250 °C 4: 90 percent / trifluoromethanesulfonic acid, trifluoroacetic acid, anisole / 2 h / Ambient temperature 5: 1.) sodium / 1.) ethanol, 0 deg C, 1,5 h, 2.) ethanol, RT, 3,5 h 6: 89 percent / conc. sulfuric acid / 1 h / 0 °C 7: sodium hydroxide, water / ethanol / 2 h / Heating 8: 73 percent / pyridine / 2 h / 100 °C View Scheme

1: 1.) sodium / 1.) ethanol, 0 deg C, 1,5 h, 2.) ethanol, RT, 3,5 h 2: 89 percent / conc. sulfuric acid / 1 h / 0 °C 3: sodium hydroxide, water / ethanol / 2 h / Heating 4: 73 percent / pyridine / 2 h / 100 °C View Scheme

1: 1.) sodium / 1.) ethanol, 0 de C,1,5 h, 2.) ethanol, RT, 3,5 h 2: 72 percent / conc. sulfuric acid / 1 h / 0 °C 3: 88 percent / sodium hydroxide, water / ethanol / 2 h / Heating 4: 13 percent / pyridine / 55 h / Heating View Scheme

1: sodium hydroxide, water / ethanol / 2 h / Heating 2: 73 percent / pyridine / 2 h / 100 °C View Scheme

1: 88 percent / sodium hydroxide, water / ethanol / 2 h / Heating 2: 13 percent / pyridine / 55 h / Heating View Scheme

1: 89 percent / conc. sulfuric acid / 1 h / 0 °C 2: sodium hydroxide, water / ethanol / 2 h / Heating 3: 73 percent / pyridine / 2 h / 100 °C View Scheme