S(OC)(O[CH3:5])(=O)=O.[OH:8][C:9]1[C:18]2[C:13](=[CH:14][CH:15]=[C:16]([NH:19][C:20](=[O:22])[CH3:21])[CH:17]=2)[N:12]=[C:11]([CH3:23])[CH:10]=1>C1(C)C=CC=CC=1>[CH3:5][O:8][C:9]1[C:18]2[C:13](=[CH:14][CH:15]=[C:16]([NH:19][C:20](=[O:22])[CH3:21])[CH:17]=2)[N:12]=[C:11]([CH3:23])[CH:10]=1Dimethyl sulfate (294 g, 2.33 mol) was charged to a suspension of hydroxyquinoline 4 (287 g, 1.33 mol) in toluene (1.5 L) and the mixture was refluxed for 6 h. After cooling to ambient temperature, the resulting dark yellow solids were collected by filtration and washed with toluene. The dry solid was dissolved in water (2.5 L) and the pH adjusted to 14 using 35% aqueous NaOH (290 g). The resulting tan precipitate was collected by filtration, washed with copious amounts of water and dried in vacuo at 60° C. to give methoxyquinoline 5 as light tan solid (259 g, 85% yield); 1H NMR (DMSO) δ 10.18 (s, 1H), 8.46 (s, 1H), 7.76 (m, 2H), 6.84 (s, 1H), 3.99 (s, 3H), 2.55 (s, 3H), 2.09 (s, 3H); 13C NMR (DMSO) δ 168.36, 160.99, 158.07, 144.86, 135.87, 128.27, 122.78, 119.26, 108.80, 101.20, 55.69, 25.08, 23.97.
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