1: With 2-fluoro-pyridine; trifluoromethylsulfonic anhydride in dichloromethane T=-78 - 0°C; Inert atmosphere; 2: With triethylsilane in dichloromethane T=0 - 25°C; Inert atmosphere; 3: With diethyl-1,4-dihydro-2,6-dimethyl-3,5-pyridine dicarboxylate in dichloromethane T=25°C; 12 h; Inert atmosphere; chemoselective reaction;

sodium tris(acetoxy)borohydride in dichloromethane T=25°C; Molecular sieve;