Hydrochloric Acid → 4-Chloro-1-methyl-3-nitro-1,2-dihydropyridin-2-one

Temperature

45 °C

A suspension of 4-chloro-3-nitro-2-pyridone (1.00 g, 5.7 mmol), potassium carbonate (1.58 g, 11.5 mmol) and methyl iodide (4.07 g, 28.7 mmol) in N,N-dimethylacetamide (5 ml) were heated at 45° C. for 18 h. The mixture was allowed to cool to ambient temperature, poured into water (100 ml), layered with ethyl acetate (50 ml) and pH adjusted to 5 by the addition of 5N hydrochloric acid. The aqueous phase was extracted into ethyl acetate (2×100 ml), the combined organics were washed with water (2×100 ml) and brine (50 ml), dried over anhydrous sodium sulfate, filtered and evaporated to give a pale yellow solid. The solid was triturated with diethyl ether (20 ml), filtered and washed with diethyl ether (5 ml) and isohexane (10 ml) and left to air dry, to give 4-chloro-1-methyl-3-nitro-1H-pyridin-2-one (0.71 g, 66%) as a pale yellow solid: δH (360 MHz, DMSO) 3.36 (1H, dd, J 5 and 3), 3.54 (6H, s), 6.69 (2H, d, J 7), 8.09 (2H, d, J 7).

1. temperatureto cool to ambient temperature
2. extractionThe aqueous phase was extracted into ethyl acetate (2×100 ml)
3. washthe combined organics were washed with water (2×100 ml) and brine (50 ml)
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. customevaporated
7. customto give a pale yellow solid
8. customThe solid was triturated with diethyl ether (20 ml)
9. filtrationfiltered
10. washwashed with diethyl ether (5 ml) and isohexane (10 ml)
11. waitleft to air
12. customdry

ORD record

ord-febdf1fea6304bf18db300e1be8f808f

Source dataset

uspto-grants-2005_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06887885B2