Methanol → Methyl 2,6-dichloropyridine-3-carboxylate

Temperature

0 °C

A solution of 2,6-dichloronicotinic acid (20.2 g, 0.105 mol) in MeOH (500 mL) was cooled to 0 ° C. and neat thionyl chloride (38 mL, 63 g, 0.525 mol) was added over ˜0.5 hours. The reaction mixture was stirred at 0° C. for 1 hour. The cooling bath was removed, the reaction temperature was allowed to warm to 25° C., and the reaction was allowed to stir for an additional 2 days at 25° C. The solvent was removed under reduced pressure to give an off-white residue. The residue was dissolved in Et2O (˜500 mL) and the resulting solution was washed successively with saturated aqueous NaHCO3 solution (˜300 mL), water (˜300 mL), and brine solution (˜300 mL). The organic layer was separated, dried over anhydrous MgSO4, and filtered. Removal of the solvent under reduced pressure yielded methyl 2,6-dichloronicotinate (21.0 g, 97%) as a white solid.

1. customThe cooling bath was removed
2. temperatureto warm to 25° C.
3. stirringto stir for an additional 2 days at 25° C
4. customThe solvent was removed under reduced pressure
5. customto give an off-white residue
6. washthe resulting solution was washed successively with saturated aqueous NaHCO3 solution (˜300 mL), water (˜300 mL), and brine solution (˜300 mL)
7. customThe organic layer was separated
8. dry with materialdried over anhydrous MgSO4
9. filtrationfiltered
10. customRemoval of the solvent under reduced pressure

ORD record

ord-3c262f0a23ce4f19a528ff0de32e701f

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07781437B2