2,3-dicyano-5,6-dichloro-p-benzoquinone in acetonitrile T=60°C; 20 h; Yields of byproduct given;

1: With (2,2′-bipyridine)nickel(II) dibromide in N,N-dimethyl-formamide T=20°C; P=760.051 Torr; Electrolysis; 2: With potassium carbonate; methyl iodide in N,N-dimethyl-formamide T=60°C; 6 h; regioselective reaction;

chloro-trimethyl-silane T=20°C; Esterification; 2 h;

1: piperidine / xylene / 3 h / Heating 2: TMSCl / 2 h / 20 °C View Scheme

1.1: pyridine / 15 h / 20 °C 2.1: (2,2′-bipyridine)nickel(II) dibromide / N,N-dimethyl-formamide / 20 °C / 760.05 Torr / Electrolysis 2.2: 6 h / 60 °C View Scheme

1: 1.) NaH / 1.) 70 deg C, 45 min, 2.) THF, 25 deg C, 4 h 2: 90 percent / Ac2O / 0.75 h / 140 °C 3: 78 percent / aq. NaOH / methanol / 2 h / Heating 4: diethyl ether 5: 86 percent / phosphorous tribromide / 1.) 25 deg C, 12 h, 2.) 80 deg C, 1 h 6: NaI / dimethylformamide / 3 h / 50 °C 7: 1,8-diazabicyclo<5.4.0>undec-7-ene (DBU) / dimethylformamide / 3 h / 80 °C View Scheme

1: diethyl ether 2: 86 percent / phosphorous tribromide / 1.) 25 deg C, 12 h, 2.) 80 deg C, 1 h 3: NaI / dimethylformamide / 3 h / 50 °C 4: 1,8-diazabicyclo<5.4.0>undec-7-ene (DBU) / dimethylformamide / 3 h / 80 °C View Scheme

1: 86 percent / phosphorous tribromide / 1.) 25 deg C, 12 h, 2.) 80 deg C, 1 h 2: NaI / dimethylformamide / 3 h / 50 °C 3: 1,8-diazabicyclo<5.4.0>undec-7-ene (DBU) / dimethylformamide / 3 h / 80 °C View Scheme

1: NaI / dimethylformamide / 3 h / 50 °C 2: 1,8-diazabicyclo<5.4.0>undec-7-ene (DBU) / dimethylformamide / 3 h / 80 °C View Scheme

1: 90 percent / Ac2O / 0.75 h / 140 °C 2: 78 percent / aq. NaOH / methanol / 2 h / Heating 3: diethyl ether 4: 86 percent / phosphorous tribromide / 1.) 25 deg C, 12 h, 2.) 80 deg C, 1 h 5: NaI / dimethylformamide / 3 h / 50 °C 6: 1,8-diazabicyclo<5.4.0>undec-7-ene (DBU) / dimethylformamide / 3 h / 80 °C View Scheme