1: [(2,5-dibromobenzene-1,4-diyl)diethyne-2,1-diyl]-bis(trimethylsilane) With n-butyllithium in diethyl ether; hexane T=-78°C; 1 h; 2: Et2NMe2SiCl in diethyl ether; hexane T=-78 - 20°C; 3: ethanol With ammonium chloride in diethyl ether; hexane T=20°C; 5 h;

potassium carbonate in tetrahydrofuran; ethanol T=20°C; 30 h;