1: 3-bromo-5-pyridine-carboxylic acid With lithium diisopropyl amide in tetrahydrofuran T=-70 - -55°C; 3.5 h; 2: 1,2-dibromo-1,1,2,2-tetrachloroethane in tetrahydrofuran T=-70 - -20°C; 2.5 h;