1,1'-carbonyldiimidazole in N,N-dimethyl-formamide Ambient temperature;

1: 65 percent / Pb(OAc)4 / acetic acid / 1 h 2: 96 percent / NaOH / ethanol; H2O / 0.5 h / Heating 3: 75 percent / 1,1'-carbonyldiimidazole / dimethylformamide / Ambient temperature View Scheme