1: 1,1'‐ethyne‐1,2‐diylbis(2‐bromo‐5‐methoxybenzene) With n-butyllithium in diethyl ether; hexane T=-30 - -25°C; 4 h; 2: Et2NMe2SiCl in diethyl ether; hexane T=-25°C; 12.5 h; 3: ethanol With ammonium chloride in tetrahydrofuran; hexane T=20°C; 23 h;