1: 42 percent / dimethylformamide / Ambient temperature 2: 48 percent / K2CO3 / dimethylformamide / 30 h 3: 70 percent / HCl / 1 h / Heating 5: 52 percent / 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) / toluene / 14 h / Heating View Scheme

1: 87 percent / NaOMe / methanol / 2 h 2: 89 percent / POCl3 / 2 h / Heating 3: 73 percent / N-bromosuccinimide, benzoyl peroxide / CCl4 / 36 h / Heating 4: 42 percent / dimethylformamide / Ambient temperature 5: 48 percent / K2CO3 / dimethylformamide / 30 h 6: 70 percent / HCl / 1 h / Heating 8: 52 percent / 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) / toluene / 14 h / Heating View Scheme

1: 55 percent / 1,2-dichloro-benzene / 2 h / Heating 2: 53 percent / POCl3 / 5 h / 120 - 125 °C 3: 48 percent / K2CO3 / dimethylformamide / 30 h 4: 70 percent / HCl / 1 h / Heating 6: 52 percent / 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) / toluene / 14 h / Heating View Scheme

1: 70 percent / 1,2-dichloro-benzene / 4 h / Heating 2: 87 percent / NaOMe / methanol / 2 h 3: 89 percent / POCl3 / 2 h / Heating 4: 73 percent / N-bromosuccinimide, benzoyl peroxide / CCl4 / 36 h / Heating 5: 42 percent / dimethylformamide / Ambient temperature 6: 48 percent / K2CO3 / dimethylformamide / 30 h 7: 70 percent / HCl / 1 h / Heating 9: 52 percent / 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) / toluene / 14 h / Heating View Scheme

pyridine T=150°C;

T=150 - 170°C;

sodium hydride in N,N-dimethyl-formamide T=60°C; 18 h;