A series crystalline compounds of methyl and phosphinyl derivatives of 2-methylquinolin-8- ol (1a) and related 5, 7-dichloro-2-methylquinolin-8-ol (1b) were quantitatively prepared and characterized by microanalysis, IR, UV–vis and multinuclear NMR spectroscopy. Five of them have been characterized by single crystal X-ray diffraction method. The known compounds, 8-methoxy-2-methylquinoline (2a) and 8-methoxyquinoline (2d), were ...