1: 3,5-dibromo-1-fluorobenzene With n-butyllithium in diethyl ether; hexane T=-80°C; 0.5 h; Inert atmosphere; 2: MeOB(pin) in tetrahydrofuran; diethyl ether; hexane T=-70°C; 0.5 h; Inert atmosphere; 3: carbon dioxide Further stages;