1: 5-bromo-5'-ethyl-2,2'-bithiophene With magnesium in diethyl ether T=35°C; Inert atmosphereReflux; 2: 2,5-dibromothiophene With (1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride in diethyl ether T=20°C; Kumada coupling reaction; Inert atmosphereCooling with ice;