Hydrochloric Acid → 2-(5,7-Difluoroquinolin-6-yl)acetic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-amino-2,6-difluorophenylacetic acid (3.2 g, 17.1 mmol), ferrous sulphate (1.04 g, 3.76 mmol), nitrobenzene (1.05 ml, 10.26 mmol) and conc. H2SO4 in glycerol (5.2 ml) was heated at 150° C. for 16 h. The mixture was cooled to RT, methanol (28 ml) was added followed by aq. 6N NaOH (28 ml) and heated at 110° C. for 3 h. After cooling to RT, the mixture was acidified with conc. HCl to pH 3.0. The precipitate formed was filtered, washed with water and dried under vacuum. The precipitate was refluxed with methanol, filtered under hot conditions and the filtrate was evaporated to give the title compound 11 g, 25%) as a brown solid, 1H-NMR (δ ppm, DMSO-d6, 400 MHz): δ12.72 (bs, 1H), 8.98 (d, J=3.1 Hz, 1H): 8.47 (d, J=8.4, 1H); 7.71 (d, J=9.7, 1H); 7.62 (dd, J=8.4, 4.1, 2H); 3.85 (s, 2H).

Provenance & Evidence