4‐Chloropyridine Hydrochloride

image [7379‐35‐3] C 5 H 4 ClN·HCl (MW 150.01) InChI =  1S/C5H4ClN.ClH/c6‐5‐1‐3‐7‐4‐2‐5;/h1‐4H;1H InChIKey =  XGAFCCUNHIMIRV‐UHFFFAOYSA‐N (reagent is an HCl salt of 4‐chloropyridine, heterocyclic building block used in metal‐catalyzed cross‐coupling reactions, nucleophilic aromatic substitutions, and lithiations) Alternative Name : 4‐chloropyridinium chloride and p ‐chloropyridine hydrochloride. Physical Data : mp 210 °C; flash point 198 °C – closed cup. Form Supplied in : beige‐yellow to white solid; widely available. Solubility : soluble in water. Handling, Storage, and Precautions : keep containers tightly closed in a dry, cool, and well‐ventilated place. Acute toxicity, oral (Category 4) H302, eye irritation (Category 2A) H319, and LD 50 oral (rat) 566 mg kg −1 . Preparative Methods : the reagent is prepared by dehydroxy‐chlorination of 4‐pyridinol, deaminative chlorination or Sandmeyer chlorination of 4‐aminopyridine, and chlorination of pyridine N ‐oxide.