2,3-dicyano-5,6-dichloro-p-benzoquinone in dichloromethane; water T=20°C; 6 h;

1: With 2,3-dicyano-5,6-dichloro-p-benzoquinone in dichloromethane; water T=20°C; 6 h; 2: With ytterbium(III) triflate in dichloromethane T=20°C; 3 h;