1: 75 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / benzene / Ambient temperature 2: HCl / H2O; ethyl acetate 3: 74 percent / potassium carbonate / dimethylformamide 4: 95 percent / KO-t-Am / toluene 5: 49 percent / aq. HCl / diethyl ether View Scheme