Carbon Dioxide → 3-Fluoropyridine-4-carboxylic acid

Participants

Reaction Steps

To a mixture of 39.9 ml of diisopropylamine and 257 ml of tetrahydrofuran was added 107 ml of a 2.64 M hexane solution of n-butyllithium under stirring while cooling the mixture in a dry ice-acetone bath, then, the mixture was stirred for 1.5 hours. Then, 25.0 g of 3-fluoropyridine was added, and the mixture was further stirred for 1.5 hours. Crushed dry ice was added to the reaction mixture, then, cooling was stopped, and the mixture was stirred until returning to room temperature. Water was added, and most of hexane and tetrahydrofuran were distilled off under reduced pressure. The residue was washed with tert-butyl methyl ether, and the aqueous layer was recovered. To the resultant aqueous layer was added concentrated hydrochloric acid under ice cool, and pH of the mixture was adjusted to 3 and the mixture was stirred for 1 hour. The deposit was collected by filtration, and dried under reduced pressure to obtain 32.51 g of 3-fluoroisonicotinic acid.

Provenance & Evidence