Hydrochloric Acid → 6-Chloro-2-methylpyridine-3-carboxylic acid

Temperatur

60 °C

Methyl 6-chloro-2-methylnicotinate (Example 423, Step 2) (900 mg, 4.85 mmol) was taken up in 2-methylpropan-2-ol (48.5 ml) and methanol (48.5 ml) and aqueous 1 molar potassium hydroxide (24.2 ml, 24.2 mmol) was added. The resulting slurry was heated at 60° C. for 4 hours, cooled to room temperature, and hydrochloric acid (1 M in water, 24.2 mL, 24.2 mmol) was added dropwise. The solution was then concentrated under reduced pressure until to afford a white solid, which was taken up in methanol and concentrated under reduced pressure. Water and ethyl acetate were added and the layers were separated. The aqueous layer was extracted with ethyl acetate three times. The combined organic layers were concentrated under reduced pressure to afford the title compound.

1. temperaturecooled to room temperature
2. concentrationThe solution was then concentrated under reduced pressure until
3. customto afford a white solid, which
4. concentrationconcentrated under reduced pressure
5. additionWater and ethyl acetate were added
6. customthe layers were separated
7. extractionThe aqueous layer was extracted with ethyl acetate three times
8. concentrationThe combined organic layers were concentrated under reduced pressure

ORD-Eintrag

ord-0c35258874e645b892156fe40896f9a9

Quelldatensatz

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08367706B2