2,3-dicyano-5,6-dichloro-p-benzoquinone or chloranil;

1: 49 percent / 85percent m-chloroperoxybenzoic acid, K2CO3 / diethyl ether / 24 h / Ambient temperature 2: 81 percent / 1.) Br2 / CH2Cl2; CHCl3 / 1.) -78 deg C, 15 min, 2.) room temp., 2 h View Scheme