Phosphorus oxychloride → 2-Chloronicotinic acid

Participants

Reaction Steps

Heat a mixture consisting of 24.4 g of 2-hydroxy nicotinic acid and 42 ml. of phosphorous oxychloride to 100°-108° C and hold for 1 hour. Add 36.4 g of phosphorous pentachloride and heat the resulting mixture at reflux for another hour. Remove the excess phosphorous oxychloride in vacuo and pour the viscous residue on ice with stirring. Age the resulting slurry at room temperature for about 12 hours. The slurry is filtered, washed and dried to yield 2-chloro-nicotinic acid, m.p. 190° C.

Provenance & Evidence