1: para-difluorobenzene With n-hexyl lithium in tetrahydrofuran; hexane T=-60°C; 1 h; 2: With zinc(II) chloride in tetrahydrofuran; hexane T=-60 - -10°C; 3: chloroacetyl chloride With copper(l) chloride in tetrahydrofuran; hexane T=-10 - 20°C; Further stages.;