Hydrochloric Acid → 2-Chloro-5-fluoronicotinic acid

Participants

Reaction Steps

Ethyl-2-chloro-5-fluoro-nicotinoate (50.4 g, 0.247 mol) (prepared according to the method of J. Med. Chem., 1993, 36(18), 2676–88, page 2684, column 2, 3rd example, ethyl-2-chloro-5-fluoropyridine-3-carboxylate) was dissolved in tetrahydrofuran (350 mL) and a 2M aqueous solution of lithium hydroxide (247 mL, 0.495 mol) added. The reaction mixture was stirred at room temperature for 3 days. The pH of the solution was reduced to pH 1 by addition of 6M hydrochloric acid and then extracted with dichloromethane (×3). The combined extracts were dried over magnesium sulphate and the solvent concentrated in vacuo to give a solid which was triturated with diethyl ether and then dried to give the title compound as a white solid, 40.56 g.

Provenance & Evidence