Ethyl Acetate → 3-Aminopyridine-2-sulfonamide

Temperature

105 °C

3-Nitro-pyridine-2-sulfonic acid amide (3 g, 14.77 mmol) and iron powder (5 g, <10 micron) were suspended in ethanol (100 mL). Saturated aqueous ammonium chloride solution (60 mL) was added and the mixture stirred at 105° C. for 1.5 h. Upon cooling to 25° C., ethyl acetate (200 mL) was added and the mixture was shaken vigorously. The entire mixture was filtered through a plug of Celite. The resulting filtrate was diluted with ethyl acetate (100 mL) and the layers were separated. The aqueous layer was back-extracted with ethyl acetate (3×200 mL). The organic layers were combined, dried over magnesium sulfate, filtered and concentrated in vacuo to dryness. The resulting solid was triturated with a 3:1 mixture of hexanes and ethyl acetate (˜10 mL). The solid was collected by vacuum filtration and dried in vacuo for 16 h to afford the desired product, 3-amino-pyridine-2-sulfonic acid amide (1.95 g, 11.27 mmol, 76%), as an off-white powder. 1H NMR (400 MHz, DMSO-d6) δ: 5.98 (2H, bs), 7.19-7.21 (1H, m), 7.32 (2H, bs), 7.79-7.80 (1H, m), 7.90-7.91 (1H, m).

1. temperatureUpon cooling to 25° C.
2. stirringthe mixture was shaken vigorously
3. filtrationThe entire mixture was filtered through a plug of Celite
4. additionThe resulting filtrate was diluted with ethyl acetate (100 mL)
5. customthe layers were separated
6. extractionThe aqueous layer was back-extracted with ethyl acetate (3×200 mL)
7. dry with materialdried over magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo to dryness
10. customThe resulting solid was triturated with a 3:1 mixture of hexanes and ethyl acetate (˜10 mL)
11. filtrationThe solid was collected by vacuum filtration
12. customdried in vacuo for 16 h

ORD record

ord-a8913b9ef68a4a59ae7c55f44c13a21e

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08101800B2