Methanol → Methyl 5-chloropyridine-2-carboxylate

Temperature

50 °C

To a solution of 5-chloropyridin-2-carboxylic acid (309 g, 1.96 mol) in anhydrous MeOH (2 L) was slowly added thionyl chloride (299.7 mL, 4.12 mol, 2.1 eq) at room temperature (cloudy solution became clear brown solution during the addition of thionyl chloride). After the addition was complete, the reaction mixture was heated to 50° C. and stirred at this temperature overnight. The solvent and excess thionyl chloride were removed under reduced pressure and the crude product was azeotroped with toluene twice. The resulting solid was transferred to a filter funnel and washed with saturated aqueous NaHCO3 until the filtrate was basic. The resulting solid was dissolved in dichloromethane (2 L) and washed with saturated aqueous NaHCO3. The organics were dried over sodium sulfate, filtered and the filtrate was concentrated to provide the title compound as an off-white solid.

1. customat room temperature
2. additionAfter the addition
3. customThe solvent and excess thionyl chloride were removed under reduced pressure
4. customthe crude product was azeotroped with toluene twice
5. customThe resulting solid was transferred to a filter funnel
6. washwashed with saturated aqueous NaHCO3 until the filtrate
7. dissolutionThe resulting solid was dissolved in dichloromethane (2 L)
8. washwashed with saturated aqueous NaHCO3
9. dry with materialThe organics were dried over sodium sulfate
10. filtrationfiltered
11. concentrationthe filtrate was concentrated

ORD record

ord-42606f2c744442ceb2f6cd6fccfccc1b

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09296736B2