1: With trimethylsilyl trifluoromethanesulfonate; N-ethyl-N,N-diisopropylamine in dichloromethane T=-78°C; 0.5 h; 2: With N-bromosuccinmide; sodium hydrogencarbonate in tetrahydrofuran T=0 - 20°C; 16 h;

1: SOCl2 / benzene / 1 h / Heating 2: diethyl ether / 1 h / 20 °C 3: 0.72 g / aq. HBr / diethyl ether / 1 h / 70 - 80 °C View Scheme

1: diethyl ether / 1 h / 20 °C 2: 0.72 g / aq. HBr / diethyl ether / 1 h / 70 - 80 °C View Scheme