Hydrochloric Acid → Methyl 3-Hydroxy-2-pyridinecarboxylate

To a solution of 3-hydroxypyridine-2-carboxylic acid (100 g, 719 mmol) in anhydrous methanol (300 ml) was added dry HCl gas until the saturation point of the solution was achieved. The reaction was heated to reflux for 15 h and then cooled and degassed with argon. The solution was concentrated in vacuo to give a white solid which was dissolved in water (250 ml). The pH of the solution was adjusted to ˜7.5 with the slow addition of solid sodium bicarbonate. The resulting suspension was extracted with EtOAc (2×300 ml), and the organic portion was dried over magnesium sulfate, filtered, and concentrated in vacuo to yield methyl 3-hydroxypyridine-2-carboxylate as an oily residue which crystallized on standing (99.2 g).

1. temperatureThe reaction was heated
2. temperatureto reflux for 15 h
3. temperaturecooled
4. customdegassed with argon
5. concentrationThe solution was concentrated in vacuo
6. customto give a white solid which
7. extractionThe resulting suspension was extracted with EtOAc (2×300 ml)
8. dry with materialthe organic portion was dried over magnesium sulfate
9. filtrationfiltered
10. concentrationconcentrated in vacuo

ORD record

ord-009d2db5fc734cd0952b92c942591da5

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08143405B2