2: aq. HCl / Heating 3: 99 percent / aq. 2M Na2CO3 / Pd(PPh3)4 / benzene / Heating 4: 85 percent / 1) NaNO2, dil. HCl, 2) NaN3 / 1) 0 degC 5: 96 percent / various solvent(s) / 180 °C View Scheme