Oxalyl chloride → Methyl 6-chloropyridine-3-carboxylate

Participants

Reaction Steps

To a solution of 6-chloronicotinic acid (20.0 g, 0.127 mol) in CH2Cl2 (250 mL) was added oxalyl chloride (123.3 mL, 0.15 mol) with 1-5 drops of DMF. The solution was stirred 18 h and concentrated in vacuo. The residue was dissolved in CH2Cl2 (100 mL) and cooled in an ice bath. To this was added MeOH (20 mL) and the solution was stirred for 15 min while maintaining a temp below 40° C. The solvent was removed in vacuo, and the residue was dissolved in Et2O, washed with H2O and brine, dried with Na2SO4, and filtered through SiO2. The solvent was removed in vacuo to yield 6-chloronicotinic acid, methyl ester (21 g) as an off-white solid: 1H-NMR (300 MHz, CDCl3) δ 9.02 (d, J=13.8 Hz, 1H), 8.51-8.06 (m, 1H), 7.76-7.30 (m, 1H), 4.01 (s, 3H); EIMS m/z 171 ([M]+), which was used in Step 2 without further purification.

Provenance & Evidence