pyridine; trifluoroacetic anhydride in diethyl ether 0.25 h; Ambient temperature;

pyridine; trifluoroacetic anhydride in diethyl ether 0.25 h; Ambient temperature;

With  hydrogenchloride in  tetrahydrofuran 0.25 h;  Ambient temperature;   

Multi-step reaction with 2 steps 1: 72 percent / NBS, α,α'-azobis(isobutyronitrile) / CCl4 / 3 h / Heating2: 70 percent / aq. HCl / tetrahydrofuran / 0.25 h / Ambient temperature