Synthesis
4-hydrazinyl-6-methoxyquinoline is prepared by adding concentrated hydrochloric acid drops of 4-chloro-6-methoxyquinoline and hydrazine monohydrate in methanol solution.To a solution of 4-chloro-6-methoxyquinoline (579 mg, 4.78 mmol) and hydrazine monohydrate (442 mg, 5.74 mmol) in methanol (8 ml), concentrated hydrochloric acid (0.48 ml) was added dropwise. The reaction mixture was left to reflux overnight with stirring. After the reaction time, the reaction mixture was left to cool at room temperature. Upon cooling, the precipitate that formed was collected by filtration, dissolved in water and basified by the addition of saturated sodium hydroxide solution until pH 9. The aqueous layer was extracted using dichloromethane (3 × 15 ml), where the organic extracts were collected, dried using magnesium sulphate and concentrated in vacuo to give the title compound as a waxy solid (200 mg, 22%).