Hydrogen Bromide → 6-Hydroxyquinoline-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

6-Methoxyquinoline-3-carboxylic acid (0.75 g, 3.69 mmol) was placed in a 20 mL microwave vial fitted with a stirbar. The solid was suspended in acetic acid (7 mL) and hydrobromic acid (48% in water, 3.5 mL) was added. The vial was capped and the suspension was carefully heated under microwave irradiation at 140° C. for 1 h. After reaction, the vial was thoroughly cooled to room temperature and very carefully vented with an 18 g needle in a fume hood prior to opening. The solids were collected by filtration and washed with ethyl acetate to afford the title product as a solid (0.678 g, 91%). LC-MS: (FA) ES+ 190; 1H NMR (400 MHz, d6-DMSO) δ ppm 10.68 (br s, 1H), 9.26 (d, J=1.9 Hz, 1H), 9.14 (d, J=1.3 Hz, 1H), 8.08 (d, J=9.1 Hz, 1H), 7.62 (dd, J=9.1, 2.7 Hz, 1H), 7.52 (d, J=2.7 Hz, 1H).

Provenance & Evidence