1: With sodium tetrafluoroborate; sodium nitrite acidic conditions; 2: T=150 - 170°C; Schieman reaction; Further stages.;

hydrogenchloride; n-butyllithium; carbon dioxide; diisopropylamine in tetrahydrofuran; pentane

1: 2-bromo-4-chloro-1-fluorobenzene With lithium diisopropyl amide in tetrahydrofuran T=-78°C; 1 h; 2: carbon dioxide in tetrahydrofuran T=-78 - 20°C;

1.1: lithium diisopropyl amide / tetrahydrofuran / 1 h / -78 °C 1.2: -78 - 20 °C 2.1: triethylamine; diphenylphosphoranyl azide / toluene / 2 h / 75 - 84 °C 2.2: 0.25 h / 35 °C 3.1: trifluoroacetic acid / dichloromethane; tetrahydrofuran / 1 h / 20 °C View Scheme

1.1: isopropylmagnesium chloride / tetrahydrofuran / 0.5 h / 0 °C 1.2: 18 h / 40 °C 2.1: potassium tert-butylate / 40 h / 40 - 50 °C 3.1: hydrogenchloride / tetrahydrofuran View Scheme