1: C18H26BrN3O4 With trifluoroacetic acid in dichloromethane 0.5 h; 2: C13H18BrN3O2; tert-butyl 4-oxo-piperidine-1-carboxylate With sodium tris(acetoxy)borohydride; triethylamine in 1,2-dichloro-ethane T=20°C; 16 h; 3: With water; sodium hydrogencarbonate in dichloromethane; 1,2-dichloro-ethane