Thionyl Chloride → 2,4-Dichloro-5-(chloromethyl)pyridine

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Reaction Steps

(4,6-Dichloro-pyridin-3-yl)-methanol (2.21 g, 12.41 mmol) is cooled under an atmosphere of argon to 0° C. Thionyl chloride (8 ml) is carefully added. After 5 minutes at 0° C., the solution is heated to reflux. After 10 minutes, TLC analysis indicated complete conversion of the starting material. After cooling to RT, excess thionyl chloride is removed via a membrane pump. The remaining oil is dissolved in EtOAc. The solution is poured into a concentrated aqueous solution of NaHCO3. The organic layer is separated and washed twice with a concentrated aqueous solution of NaCl. After drying over Na2SO4, the organic solvent is removed to afford the title compound of adequate purity for immediate further use. 1H NMR (CDCl3, 400 MHz): δ 4.65 (s, 2H), 7.42 (s, 1H), 8.44 (s,1H). ES+−MS: 195, 197, 199 (3 Cl) [M+H]+.

Provenance & Evidence