Sodium borohydride → 4-Amino-3-pyridinesulfonamide

Temperature

25 °C

4-Azido-pyridine-3-sulfonic acid amide (3.75 g, 18.83 mmol) was dissolved in methanol (80 mL). Sodium borohydride (0.712 g, 18.83 mmol) was carefully added portionwise. Vigorous effervescence was observed. The mixture continued to stir at 25° C. for 25 min. The mixture was concentrated in vacuo to a thick yellow sludge. The residue was dissolved in a mixture of ethyl acetate (200 mL) and saturated aqueous ammonium chloride solution (200 mL). The aqueous layer was back extracted with ethyl acetate (6×200 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated in vacuo to afford the desired product, 4-amino-pyridine-3-sulfonic acid amide (1.8 g, 10.4 mmol, 55%), as a pale yellow solid. 1H NMR (400 MHz, DMSO-d6) δ: 6.63 (2H, bs), 6.68 (1H, d, J=5.4 Hz), 7.40 (2H, bs), 8.06 (1H, d, J=5.5 Hz), 8.43 (1H, s).

1. concentrationThe mixture was concentrated in vacuo to a thick yellow sludge
2. dissolutionThe residue was dissolved in a mixture of ethyl acetate (200 mL) and saturated aqueous ammonium chloride solution (200 mL)
3. extractionThe aqueous layer was back extracted with ethyl acetate (6×200 mL)
4. dry with materialThe combined organic layers were dried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo

ORD record

ord-4ddd11507ad3480fa11aaf6f5f34534e

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08765741B2