1: in toluene T=65°C; Schlenk techniqueInert atmosphere; 2: With N-bromosuccinmide in toluene T=-78°C; Schlenk techniqueInert atmosphere; 3: With water in toluene T=20°C; 1 h; Schlenk techniqueInert atmosphere; regioselective reaction;

1.1: thionyl chloride; N,N-dimethyl-formamide / dichloromethane / 2.33 h / 0 - 20 °C 2.1: dichloromethane; tetrahydrofuran / 20 °C / |Cooling with ice 3.1: toluene / 65 °C / |Schlenk technique; |Inert atmosphere 3.2: -78 °C / |Schlenk technique; |Inert atmosphere 3.3: 1 h / 20 °C / |Schlenk technique; |Inert atmosphere View Scheme

potassium chlorate; bromine

1.1: dichloromethane; tetrahydrofuran / 20 °C / |Cooling with ice 2.1: toluene / 65 °C / |Schlenk technique; |Inert atmosphere 2.2: -78 °C / |Schlenk technique; |Inert atmosphere 2.3: 1 h / 20 °C / |Schlenk technique; |Inert atmosphere View Scheme