in cyclohexane 12 h; Heating;

4-(N,N-dimethlyamino)pyridine; triethylamine T=-20°C; 72 h;

1: 87 percent / triethyl amine / dimethylformamide / 60 h / Heating 2: 70 percent / DDQ, 2,4,6-collidine / benzene / 7 h / 0 - 3 °C 3: 87 percent / triethyl amine, 4-(dimethylamino)pyridine / 72 h / -20 °C View Scheme

1: 70 percent / DDQ, 2,4,6-collidine / benzene / 7 h / 0 - 3 °C 2: 87 percent / triethyl amine, 4-(dimethylamino)pyridine / 72 h / -20 °C View Scheme