potassium dichromate; sulfuric acid

1.1: 75 percent / SnCl2*2H2O; HCl / methanol / cooling 2.1: aq. HBr; NaNO2 / H2O / 0.17 h / 0 °C 2.2: 58 percent / CuSO4*5H2O; Cu; aq. HBr / H2O / 0.5 h / 80 °C View Scheme

1: tin (II)-chloride; hydrogen chloride; ethanol 2: Diazotization.Behandlung der Diazoniumsalz-Loesung mit CuBr in wss. HBr in der Waerme 3: tin (II)-chloride; hydrogen chloride; ethanol View Scheme