205448-31-3

Brown solid

General procedure for the synthesis of 7-hydroxy-4-chloro-6-methoxyquinoline from 7-(benzyloxy)-4-chloro-6-methoxyquinoline: the compound 7-(benzyloxy)-4-chloro-6-methoxyquinoline (16 g, 53.37 mmol) was dissolved in trifluoroacetic acid (100 mL), and methanesulfonic acid (6.1 mL, 93.94 mmol) was added in one go. The reaction mixture was stirred under reflux conditions for 3 hours and subsequently cooled to room temperature. The solvent was removed by evaporation and the pH of the residue was adjusted to 7 with 2.5 N sodium hydroxide solution.The resulting solid was crushed into small pieces and the mixture was stirred vigorously for 2 hr. The solid was collected by filtration and dried under high vacuum to give 7-hydroxy-4-chloro-6-methoxyquinoline (11.3 g, yield = 100%) as a light brown solid.

[1] Journal of Medicinal Chemistry, 2008, vol. 51, # 18, p. 5766 - 5779
[2] Patent: US2014/235634, 2014, A1. Location in patent: Paragraph 0356; 0362
[3] Patent: CN106749231, 2017, A. Location in patent: Paragraph 0080; 0081; 0092; 0093