N-bromobutanimide → 5-Bromo-6-methoxy-2-methylquinoline

Beteiligte Stoffe

Reaktionsschritte

A solution of 6-methoxy-2-methylquinoline (177 g, 1.02 mol) in acetonitrile (1.77 L) was cooled to 0-3° C. followed by portion-wise addition of N-bromo-succinimide (200 g, 1.12 mol) over a period of 30 min while maintaining the same temperature. The resulted brown slurry was warmed to ambient temperature and stirred for an additional 6 h. The reaction was then quenched by a 10% NaHSO3 solution (211 mL). The reaction mixture was concentrated to a volume of 600 mL then slowly poured into 0.1 N NaOH (2.5 L). The slurry (pH=9) was stirred at room temperature for 1 h then filtered, washed with water (2×1 L) and dried in a vacuum oven to give 253 g (98.6%) of the title compound as a brown solid. Rf=0.39 (3:7) EtOAc:heptane; 1H NMR (DMSO) δ 8.30 (d, J=6.5 Hz, 1H), 7.98 (d, J=6.9 Hz, 1H), 7.70 (d, J=7.0 Hz, 1H), 7.47 (d, J=6.5 Hz, 1H), 4.02 (s, 3H), 2.66 (s, 3H);

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