1: triethylamine, ethyl chloroformate / CHCl3 / 1.) -5 degC, 30 min., 2.) heating to bp. 2: 40percent HBr / acetic acid View Scheme

hydrogen bromide in acetic acid Ambient temperatureovernight; Yield given;

1: 1.) Triethylamine, ethyl carbonochloridate / 1.) CHCl3, - 5 deg C, 20 min, 2.) reflux, 30 min 2: KF*2H2O, 18-crown-6 / methanol / 0.08 h / Heating 3: HBr / acetic acid / Ambient temperature; overnight View Scheme

1: KF*2H2O, 18-crown-6 / methanol / 0.08 h / Heating 2: HBr / acetic acid / Ambient temperature; overnight View Scheme

1: triethylamine, ethyl chloroformate / CHCl3 / 1.) -5 degC, 30 min., 2.) heating to bp. 2: 40percent HBr / acetic acid View Scheme