To a stirred mixture of 4(3-bromophenylamino)-6,7-dihydroxy-3-quinolinecarbonitrile (1.07 g, 3.0 mmol), potassium carbonate (1.66 g, 12.0 mmol), and 12 ml of DMF at 0° C. was added 1-iodopropane (1.17 ml, 12.0 mmol). The mixture was warmed to 25° C., stirred for 5 h, and then partioned at 0° C. with ethyl acetate and water containing HCl to give pH-8. The organic layer was separated, washed with water, dried, and concentrated. The residue was subjected to chromatography on silica gel with methylene chloride-ethyl acetate-acetic acid to give an amorphous solid; mass spectrum (electrospray, m/e) M+H 440.2, 442.2.
