2,6-Dichloro-5-fluoronicotinic acid

82671-03-2

82671-06-5

The general procedure for the synthesis of 2,6-dichloro-5-fluoropyridine-3-carboxylic acid from ethyl 2,6-dichloro-5-fluoropyridine-3-carboxylate is as follows: Example 1: 1. ethyl 2,6-dichloro-5-fluoropyridine-3-carboxylate (20 g, 84 mmol) was dissolved in a mixture of 40 mL of trifluoroacetic acid and 40 mL of 7.5N hydrochloric acid. 2. The mixture was heated to reflux and kept reacting for 24 hours. 3. Upon completion of the reaction, the solution was cooled and the trifluoroacetic acid was removed by evaporation under reduced pressure. 4. After cooling to room temperature, 100 mL of water was added, at which point a white precipitate formed in the solution. 5. The precipitate was collected by filtration, washed with hexane, and dried to give 12.91 g (73.2% yield) of 2,6-dichloro-5-fluoropyridine-3-carboxylic acid, with a melting point of 153-154 °C. The reaction was completed with the addition of 100 mL of water.