pyridine 6 h; Reflux;

1: bromine / chloroform / 0 - 5 °C / Reflux 2: pyridine / 6 h / Reflux View Scheme

1.1: hydrogenchloride / water / 0.5 h / Reflux 1.2: 4 h / 20 °C / Reflux 2.1: bromine / chloroform / 0 - 5 °C / Reflux 3.1: pyridine / 6 h / Reflux View Scheme

1.1: pyridine / 4 h / Reflux 2.1: pyridine / 3 h / 0 - 5 °C 3.1: sodium dithionite 4.1: sulfuric acid / ethanol; benzene / Reflux 4.2: Cooling with ice View Scheme

1: With sulfuric acid in ethanol; benzene Reflux; 2: With sodium nitrite in ethanol; benzene Cooling with ice;

1.1: hydrogenchloride; sodium nitrite / water / 5 °C / Cooling with ice 2.1: phosphorus pentachloride 3.1: pyridine / 4 h / Reflux 4.1: pyridine / 3 h / 0 - 5 °C 5.1: sodium dithionite 6.1: sulfuric acid / ethanol; benzene / Reflux 6.2: Cooling with ice View Scheme