Hydrochloric Acid → 3-Chloropyridine-2-carboxylic acid

64.1 g of 10B was refluxed in 460 ml of 2N aqueous sodium hydroxide solution for 1 hour. The mixture was cooled, acidified to pH=2.5 with concentrated hydrochloric acid, stripped of water under reduced pressure, then azeotroped with methanol. The residue was stirred with 250 ml of a 1:1 v:v mixture of methylene chloride and methanol, and the resulting mixture was filtered. The filtrate was stripped of volatiles (water bath temperature 60° C). This purification procedure was repeated, to give 3-chloropicolinic acid (10C), as a yellow solid, m.p.: 125.5°-127.5° C.

1. temperatureThe mixture was cooled
2. customazeotroped with methanol
3. additionv mixture of methylene chloride and methanol
4. filtrationthe resulting mixture was filtered
5. customwas stripped of volatiles (water bath temperature 60° C)
6. customThis purification procedure

ORD record

ord-0db6419b58f04eadafd778a5ff055688

Source dataset

uspto-grants-1989_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04853027