boron tribromide in dichloromethane 12 h; Ambient temperature;

2,3-dicyano-5,6-dichloro-p-benzoquinone in benzene 0.5 h; Heating; Yield given;

1: 23 percent / hydroquinone / 30 h / 160 °C 2: m-chloroperbenzoic acid / tetrahydrofuran / 2 h / Ambient temperature 3: 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 0.5 h / Heating View Scheme

1: m-chloroperbenzoic acid / tetrahydrofuran / 2 h / Ambient temperature 2: 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 0.5 h / Heating View Scheme

1: 60 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 1 h / Heating 2: 74 percent / BBr3 / CH2Cl2 / 12 h / Ambient temperature View Scheme