Dichloromethane → Methyl 2-chloropyridine-4-carboxylate

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Reaction Steps

2-Chloro-isonicotinic acid (10 g, 63.5 mmol)) was refluxed in thionylchloride (40 mL) under argon for 6 hr. The SOCl2 was evaporated under reduced pressure, twice toluene (30 mL) was added and evaporated. The residue was dried under high vacuum and set under argon. MeOH (50 mL) was added and the mixture was heated to reflux for 1 hr. and stirred overnight at r.t. The solvent was evaporated. To the residue were added saturated NaHCO3 and ether. The etheral phase was separated, washed with water, brine, dried over MgSO4 and evaporated. The residue was purified by column chromatography using CH2Cl2 as eluent to give 9.1 g (84%) of the white and crystalline product. Rf (CH2Cl2)=0.51. 1H NMR (599 MHz, CDCl3) δ 8.52 (d, 1H, J=5.26 Hz, pyridine), 7.87 (d, 1H, J=1.31 Hz, pyridine) 7.75 (dd, 1H, J=5.26, 1.31 Hz, pyridine), 3.95 (s, 3H, methyl ester). 13C NMR (150 MHz, CDCl3) δ 164.5, 152.7, 150.8, 140.4, 124.3, 121.8, 53.2. HRMS (MALDI-FTMS): MH+ calculated: 172.016; found: 172.0161

Provenance & Evidence