1: 2,6-difluoro-1-bromobenzene With isopropylmagnesium chloride in tetrahydrofuran; diethyl ether T=-20 - 0°C; 1 h; Inert atmosphere; 2: boron trifluoride diethyl etherate in tetrahydrofuran; diethyl ether T=-50 - 20°C; 1 h; Inert atmosphere;

magnesium in tetrahydrofuran; toluene addn. of 50mmol F2C6H3Br in 20ml THF to 50mmol Mg-filings in 50ml THF at -20°C; warming to room temp. after 4h; stirring for 14h; dropwise addn. of the mixture to 17mmol BCl3*OMe2 in 70ml toluene at -20°C; warming to room temp. after 4h;; removal of solvent; refluxing with n-hexane for 4h; removal of Mg-salts by filtration; crystn. from the filtrate; recrystn. from n-hexane; detn. by (13)C-, (19)F-, (1)H-NMR, m.p., mass spectroscopy;;

1.1: magnesium / -20 - 20 °C / |Inert atmosphere; |Schlenk technique; |Glovebox 1.2: 4 h / -20 °C / |Inert atmosphere 2.1: dimethylmono-chlorosilane / 3 h / 20 °C / |Inert atmosphere; |Schlenk technique; |Glovebox View Scheme