sulfuric acid

potassium carbonate in dichloromethane; acetone 6 h; Heating;

1: 3.78 g / pyridine / 0.03 h / microwave irradiation 2: 4.58 g / KOH / pyridine / 0.1 h / microwave irradiation 3: 2.03 g / conc. H2SO4 / acetic acid / 0.05 h / microwave irradiation View Scheme

1: pyridine 2: NaNH2; toluene 3: concentrated sulfuric acid View Scheme

1: lithium hexamethyldisilazane / tetrahydrofuran / -30 - 0 °C / Inert atmosphere 2: trifluoroacetic acid / methanol / 24 h / 50 °C View Scheme

1.1: titanium tetrachloride / dichloromethane / 0 - 20 °C / Inert atmosphere 2.1: selenium(IV) oxide; dihydrogen peroxide / tert-butyl alcohol / 1.5 h / 50 °C 3.1: triethylamine / methanol / 0 - 20 °C 4.1: potassium carbonate / acetone / 0 - 20 °C / Inert atmosphere 5.1: trichlorophosphate / 0.33 h / 20 °C 5.2: 6 h / 60 °C 6.1: selenium(IV) oxide; dihydrogen peroxide / tert-butyl alcohol / 2.5 h / 50 °C 7.1: triethylamine / methanol / 0 - 20 °C 8.1: potassium carbonate / acetone / 36 h / 20 °C / Inert atmosphere 9.1: AlCl3, aluminium chloride / dichloromethane / 0 - 20 °C 10.1: lithium hexamethyldisilazane / tetrahydrofuran / -30 - 0 °C / Inert atmosphere 11.1: trifluoroacetic acid / methanol / 24 h / 50 °C View Scheme

1.1: trichlorophosphate / 0.33 h / 20 °C 1.2: 6 h / 60 °C 2.1: selenium(IV) oxide; dihydrogen peroxide / tert-butyl alcohol / 2.5 h / 50 °C 3.1: triethylamine / methanol / 0 - 20 °C 4.1: potassium carbonate / acetone / 36 h / 20 °C / Inert atmosphere 5.1: AlCl3, aluminium chloride / dichloromethane / 0 - 20 °C 6.1: lithium hexamethyldisilazane / tetrahydrofuran / -30 - 0 °C / Inert atmosphere 7.1: trifluoroacetic acid / methanol / 24 h / 50 °C View Scheme

1: AlCl3, aluminium chloride / dichloromethane / 0 - 20 °C 2: lithium hexamethyldisilazane / tetrahydrofuran / -30 - 0 °C / Inert atmosphere 3: trifluoroacetic acid / methanol / 24 h / 50 °C View Scheme

1: AlCl3, aluminium chloride / dichloromethane / 0 - 20 °C / Inert atmosphere 2: potassium carbonate / N,N-dimethyl-formamide / 1.5 h / 60 °C / Inert atmosphere 3: selenium(IV) oxide; dihydrogen peroxide / tert-butyl alcohol / 10 h / 50 °C / Inert atmosphere 4: potassium carbonate / methanol / 3 h / 20 °C / Inert atmosphere 5: potassium carbonate / acetone / 9.5 h / 20 °C / Inert atmosphere 6: AlCl3, aluminium chloride / dichloromethane / 0 - 20 °C 7: lithium hexamethyldisilazane / tetrahydrofuran / -30 - 0 °C / Inert atmosphere 8: trifluoroacetic acid / methanol / 24 h / 50 °C View Scheme

1: potassium carbonate / N,N-dimethyl-formamide / 1.5 h / 60 °C / Inert atmosphere 2: selenium(IV) oxide; dihydrogen peroxide / tert-butyl alcohol / 10 h / 50 °C / Inert atmosphere 3: potassium carbonate / methanol / 3 h / 20 °C / Inert atmosphere 4: potassium carbonate / acetone / 9.5 h / 20 °C / Inert atmosphere 5: AlCl3, aluminium chloride / dichloromethane / 0 - 20 °C 6: lithium hexamethyldisilazane / tetrahydrofuran / -30 - 0 °C / Inert atmosphere 7: trifluoroacetic acid / methanol / 24 h / 50 °C View Scheme