bromine in acetic acid T=90°C; 96 h;

1.1: bromine; triphenylphosphine 2.1: 1,8-diazabicyclo[5.4.0]undec-7-ene / N,N-dimethyl-formamide / 20 °C 3.1: hydrazine hydrate / methanol; dichloromethane / 20 °C 4.1: sodium hydrogencarbonate / 1,4-dioxane; water / 0.5 h / 20 °C 4.2: 1 h 5.1: bis(sym-collidine)iodine(I) hexafluorophosphate / dichloromethane / 0.5 h / 20 °C 6.1: N-bromosuccinmide; boron trifluoride diethyl etherate / dichloromethane / 0.25 h / 0 °C View Scheme

1.1: 1,8-diazabicyclo[5.4.0]undec-7-ene / N,N-dimethyl-formamide / 20 °C 2.1: hydrazine hydrate / methanol; dichloromethane / 20 °C 3.1: sodium hydrogencarbonate / 1,4-dioxane; water / 0.5 h / 20 °C 3.2: 1 h 4.1: bis(sym-collidine)iodine(I) hexafluorophosphate / dichloromethane / 0.5 h / 20 °C 5.1: N-bromosuccinmide; boron trifluoride diethyl etherate / dichloromethane / 0.25 h / 0 °C View Scheme