1: 1-bromo-6-chloro-hexane With magnesium; lithium chloride; zinc(II) chloride in tetrahydrofuran T=20°C; 0.666667 h; Inert atmosphere; 2: With CuCN*2LiCl in tetrahydrofuran T=-30°C; Inert atmosphere; 3: o-chloro benzoic acid chloride in tetrahydrofuran T=-30°C; Inert atmosphere;