Hydrochloric Acid → 3-Chloropyridine-2-carboxylic acid

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Reaction Steps

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.

Provenance & Evidence