N-bromosuccinmide; n-Bu4NH2F3 in dichloromethane 1 h; Ambient temperature;

1: 1.) butyllithium / 1.) THF, 0-20 deg C, 12 h, 2.) 0-20 deg C, 5 h 2: 99 percent / tetrabutylammonium dihydrogentrifluoride, NBS / CH2Cl2 / 1 h / Ambient temperature View Scheme

1: 85 percent / sodium borohydride, acetic acid, sodium acetate, sodium sulfate / ethanol / Ambient temperature 2: 1.) butyllithium / 1.) THF, 0-20 deg C, 12 h, 2.) 0-20 deg C, 5 h 3: 99 percent / tetrabutylammonium dihydrogentrifluoride, NBS / CH2Cl2 / 1 h / Ambient temperature View Scheme

1: 85 percent / sodium borohydride, acetic acid, sodium acetate, sodium sulfate / ethanol / Ambient temperature 2: 1.) butyllithium / 1.) THF, 0-20 deg C, 12 h, 2.) 0-20 deg C, 5 h 3: 99 percent / tetrabutylammonium dihydrogentrifluoride, NBS / CH2Cl2 / 1 h / Ambient temperature View Scheme