1.1: acetic anhydride / 2 h / 110 °C 2.1: magnesium / tetrahydrofuran / 0.5 h / 40 °C 2.2: 1 h / 40 °C View Scheme

2,3-dicyano-5,6-dichloro-p-benzoquinone in acetonitrile 0.5 h; Photolysis; Title compound not separated from byproducts;

acetic anhydride T=110°C; 2 h;

2,3-dicyano-5,6-dichloro-p-benzoquinone in acetonitrile 0.5 h; Photolysis; Title compound not separated from byproducts;

1.1: acetic anhydride / 2 h / 110 °C 2.1: magnesium / tetrahydrofuran / 0.5 h / 40 °C 2.2: 1 h / 40 °C 3.1: nitric acid / dichloromethane / 12 h / 10 - 20 °C 4.1: sodium hydroxide / 2 h / 0 - 20 °C 5.1: lithium chloride / N,N-dimethyl-formamide / 6 h / |Reflux 6.1: sodium carbonate; sodium dithionite; water / 1 h / 20 °C 7.1: trifluoroacetic acid / toluene / 6 h / 80 °C View Scheme

1.1: acetic anhydride / 2 h / 110 °C 2.1: magnesium / tetrahydrofuran / 0.5 h / 40 °C 2.2: 1 h / 40 °C 3.1: nitric acid / dichloromethane / 12 h / 10 - 20 °C 4.1: sodium hydroxide / 2 h / 0 - 20 °C 5.1: lithium chloride / N,N-dimethyl-formamide / 6 h / |Reflux 6.1: sodium carbonate; sodium dithionite; water / 1 h / 20 °C 7.1: trifluoroacetic acid / toluene / 6 h / 80 °C 8.1: triethylamine; pyridine / 2 h / 20 °C / |Inert atmosphere View Scheme

1.1: N-chloro-succinimide; pyridine / tetrahydrofuran / 0.67 h / 60 °C / |Inert atmosphere 1.2: 2 h / 50 °C / |Inert atmosphere 2.1: pyridinium chlorochromate / dichloromethane / 4 h / 20 °C / |Molecular sieve View Scheme

1.1: acetic anhydride / 2 h / 110 °C 2.1: magnesium / tetrahydrofuran / 0.5 h / 40 °C 2.2: 1 h / 40 °C 3.1: nitric acid / dichloromethane / 12 h / 10 - 20 °C 4.1: sodium hydroxide / 2 h / 0 - 20 °C 5.1: lithium chloride / N,N-dimethyl-formamide / 6 h / |Reflux 6.1: sodium carbonate; sodium dithionite; water / 1 h / 20 °C 7.1: trifluoroacetic acid / toluene / 6 h / 80 °C View Scheme

1.1: acetic anhydride / 2 h / 110 °C 2.1: magnesium / tetrahydrofuran / 0.5 h / 40 °C 2.2: 1 h / 40 °C 3.1: nitric acid / dichloromethane / 12 h / 10 - 20 °C 4.1: sodium hydroxide / 2 h / 0 - 20 °C 5.1: lithium chloride / N,N-dimethyl-formamide / 6 h / |Reflux 6.1: sodium carbonate; sodium dithionite; water / 1 h / 20 °C 7.1: trifluoroacetic acid / toluene / 6 h / 80 °C 8.1: triethylamine; pyridine / 2 h / 20 °C / |Inert atmosphere 9.1: hydrogenchloride; water / 3 h / 20 - 70 °C View Scheme

1: N-chloro-succinimide / N,N-dimethyl-formamide / 2 h / 20 - 35 °C 2: triethylamine / diethyl ether / 0 - 20 °C 3: lithium aluminium tetrahydride / tetrahydrofuran / 3 h / 20 °C View Scheme