Methanol → Methyl 2,5-Dichloronicotinate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 2,5-dichloronicotinic acid (20.2 g, 0.105 mol, Aldrich) in methanol (500 mL) was cooled to 0° C. and neat thionyl chloride (38 mL, 63 g, 0.525 mol) was added over ˜30 min. The reaction mixture was stirred at 0° C. for 1 hour. The cooling bath was removed, the reaction temperature was allowed to warm to room temperature, and the reaction was allowed to stir for an additional 2 days at room temperature. The solvent was removed under reduced pressure to give an off-white residue. The residue was dissolved in ether (˜500 mL) and the resulting solution was washed successively with saturated aqueous sodium bicarbonate solution (˜300 mL), water (˜300 mL), and brine (˜300 mL). The organic layer was separated, dried over anhydrous magnesium sulfate, and filtered. Removal of the solvent under reduced pressure yielded methyl 2,5-dichloronicotinate (21.0 g, 97% yield) as a white solid.

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