Formic Acid → 2-(tetrahydro-2H-pyran-4-yloxy)pyridin-3-amine

Temperature

50 °C

To a solution of 3-nitro-2-(tetrahydro-2H-pyran-4-yloxy)pyridine (2.31 g, 10.3 mmol) in anhydrous MeOH (20 mL) was added ammonium formate (1.2 g, 19.1 mmol) and palladium hydroxide on carbon (20%, 0.40 g). The mixture was stirred at ambient temperature for 8 hours when an additional aliquot of ammonium formate (1.0 g) was added. The mixture was heated at 50° C. for 4 hours, the solution adjusted to pH 8 with formic acid before further heating at 50° C. for one hour. The reaction was filtered through Celite and the catalyst residue washed with MeOH. The solvent was concentrated in vacuo to give a deep purple solid. The crude product was purified by ion-exchange chromatography (SCX-2 eluting with hydrochloric acid/MeOH ammonia/MeOH). The product crystallised as a white solid (1.8 g, 90%).

1. additionwas added
2. temperaturebefore further heating at 50° C. for one hour
3. filtrationThe reaction was filtered through Celite
4. washthe catalyst residue washed with MeOH
5. concentrationThe solvent was concentrated in vacuo
6. customto give a deep purple solid
7. customThe crude product was purified by ion-exchange chromatography (SCX-2 eluting with hydrochloric acid/MeOH ammonia/MeOH)
8. customThe product crystallised as a white solid (1.8 g, 90%)

ORD record

ord-ae76f51eb7ce4f72944d1c3547d07d08

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08486953B2