Potassium Carbonate → 2-(methylamino)pyridine-3-carboxylic acid

Temperature

100 °C

Methylamine hydrochloride (8.6 g, 128 mmol) was added portionwise to a mixture of 2-chloronicotinic acid (10.0 g, 64 mmol), potassium carbonate (35.4 g, 256 mmol) and copper (I) bromide (920 mg, 6.4 mmol) in N,N-dimethylformamide (100 ml), and the reaction heated at 100° C. for 18 hours, then cooled. The resulting precipitate was removed by filtration, washing through with additional methanol and the filtrate evaporated under reduced pressure. The residue was redissolved in 2N sodium hydroxide solution (200 ml), washed with diethyl ether (4×80 ml), then the pH of the aqueous solution adjusted to 6, using concentrated hydrochloric acid. This aqueous solution was evaporated under reduced pressure, the residue dissolved in methanol, poly(4-vinylpyridine), 2% cross-linked (5 g) was added, and the mixture stirred at room temperature for 18 hours. The resin was removed by filtration, and the procedure then repeated. The solution was evaporated under reduced pressure, and the solid recrystallised from ethanol, to afford the title compound, 5.2 g.

1. temperaturecooled
2. customThe resulting precipitate was removed by filtration
3. washwashing through with additional methanol
4. customthe filtrate evaporated under reduced pressure
5. dissolutionThe residue was redissolved in 2N sodium hydroxide solution (200 ml)
6. washwashed with diethyl ether (4×80 ml)
7. customThis aqueous solution was evaporated under reduced pressure
8. dissolutionthe residue dissolved in methanol
9. additionpoly(4-vinylpyridine), 2% cross-linked (5 g) was added
10. customThe resin was removed by filtration
11. customThe solution was evaporated under reduced pressure
12. customthe solid recrystallised from ethanol

ORD record

ord-f62e92424b8d45ffb826e7278bd7e8c0

Source dataset

uspto-grants-2005_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06914160B1