sulfuric acid; iodine; acetic acid; sodium sulfate; ethanol in water

1: 1,4-Diiodobenzene With N,N,N',N'-tetramethyl-urea; zinc T=130°C; 72 h; 2: 1-ethyl-4-iodobenzene With tri-tert-butyl phosphine; N,N,N',N'-tetramethyl-urea; bis(benzonitrile)palladium(II) dichloride in tetrahydrofuran T=20°C; Negishi reaction; 1 h; 3: With iodine in tetrahydrofuran T=20°C; 3 h; Further stages.;

potassium hydroxide; hydrazine hydrate in diethylene glycol T=210 - 220°C;

1: AlCl3 2: aq. N2H4, KOH / bis-(2-hydroxy-ethyl) ether / 210 - 220 °C View Scheme