6-Bromoquinoline-2-carboxylic acid synthesis

Yield: 96%

Reaction Conditions:

with sulfuric acid;water at 150; for 5.25 h;

Steps:

1.1b
1b) 6-Bromo-2-quinolinecarboxylic Acid Concentrated sulfuric acid (0.75 L) was added during 15 min to a stirred suspension of 6-bromo-2-(tribromomethyl)quinoline (350 g, 0.76 mol) in water (1.75 L). The resulting suspension was heated at 150° C. (bath temperature) for 5 hr. The mixture was cooled and the precipitate was collected by filtration, washed with water and dried to give 6-bromo-2-quinolinecarboxylic acid as a solid (127.6 g). The filtrate was diluted with water (3 L) and a second crop of the product was obtained (55.7 g, combined yield 183.3 g, 96%). ¹H NMR (400 MHz, DMSO-d₆): δ 8.50 (d, J=9 Hz, 1H), 8.38 (d, J=2 Hz, 1H), 8.13 (d, J=9 Hz, 1H), 8.06 (d, J=9 Hz, 1H), 7.96 (m, 1H). ES-LCMS m/z 253 (M+H)⁺.

References:

SmithKline Beecham Corporation US2008/96921, 2008, A1 Location in patent:Page/Page column 32