1: bis-diphenylphosphine With potassium hydride; diphenylphosphine oxide in toluene T=20 - 120°C; Inert atmosphere; 2: (S)-2-(2-fluorophenyl)-4-isopropyl-5,5-dimethyl-4,5-dihydrooxazole in toluene T=120°C; Inert atmosphere;

copper(l) iodide; caesium carbonate; N-methyl-2-(methylamino)ethylamine in toluene T=20 - 110°C; Ullmann type coupling; Inert atmosphere;

1: thionyl chloride / 65 °C / Inert atmosphere 2: sodium hydrogencarbonate / tetrahydrofuran; methanol / 0 - 20 °C / Inert atmosphere 3: tetrahydrofuran / 0 - 20 °C / Inert atmosphere 4: hydrogenchloride; water / 1,4-dioxane / Inert atmosphere 5: triethylamine / 1,4-dioxane / 2 h / 0 °C / Inert atmosphere 6: methanesulfonic acid / dichloromethane / 0 - 20 °C / Inert atmosphere 7: potassium hydride / toluene / 20 - 120 °C / Inert atmosphere View Scheme

1: tetrahydrofuran / 0 - 20 °C / Inert atmosphere 2: hydrogenchloride; water / 1,4-dioxane / Inert atmosphere 3: triethylamine / 1,4-dioxane / 2 h / 0 °C / Inert atmosphere 4: methanesulfonic acid / dichloromethane / 0 - 20 °C / Inert atmosphere 5: potassium hydride / toluene / 20 - 120 °C / Inert atmosphere View Scheme

1: sodium hydrogencarbonate / tetrahydrofuran; methanol / 0 - 20 °C / Inert atmosphere 2: tetrahydrofuran / 0 - 20 °C / Inert atmosphere 3: hydrogenchloride; water / 1,4-dioxane / Inert atmosphere 4: triethylamine / 1,4-dioxane / 2 h / 0 °C / Inert atmosphere 5: methanesulfonic acid / dichloromethane / 0 - 20 °C / Inert atmosphere 6: potassium hydride / toluene / 20 - 120 °C / Inert atmosphere View Scheme

1: hydrogenchloride; water / 1,4-dioxane / Inert atmosphere 2: triethylamine / 1,4-dioxane / 2 h / 0 °C / Inert atmosphere 3: methanesulfonic acid / dichloromethane / 0 - 20 °C / Inert atmosphere 4: potassium hydride / toluene / 20 - 120 °C / Inert atmosphere View Scheme