Formaldehyde → 2-Dimethylaminopyridine

Temperature

0 °C

To an ice-cold solution of 2-aminopyridine (5.0 g, 53.12 mmol) in acetonitrile (150.0 mL) was added sequentially water (33.0 mL) followed by formaldehyde (37% aq. solution, 50.0 mL) and sodium cyanoborohydride (10.0 g, 159.13 mmol). The resulting reaction mixture was stirred at 0° C. for 10 min followed by drop wise addition of acetic acid (12.0 mL). The reaction mixture was then allowed to stir at room temperature for 15 h. After the completion of the reaction (TLC monitoring), the solvent was evaporated and the residue was treated with aqueous NaOH (2N, 50.0 mL) and extracted with hexane (3×50.0 mL). The combined organics was washed with brine, dried (Na2SO4), filtered and concentrated. The residue was purified over silica gel (100-200 M, 2% EtOAc-Hexane) to get the desired compound (3.50 g, 55%).

1. customThe resulting reaction mixture
2. stirringto stir at room temperature for 15 h
3. customAfter the completion of the reaction (TLC monitoring)
4. customthe solvent was evaporated
5. additionthe residue was treated with aqueous NaOH (2N, 50.0 mL)
6. extractionextracted with hexane (3×50.0 mL)
7. washThe combined organics was washed with brine
8. dry with materialdried (Na2SO4)
9. filtrationfiltered
10. concentrationconcentrated
11. customThe residue was purified over silica gel (100-200 M, 2% EtOAc-Hexane)

ORD record

ord-d8d15cc0be404311aafdc49267ca0ed9

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08389516B2