Sodium Hydroxide → 5-Hydrazino-2-pyridinesulfonamide hydrochloride

Temperature

0 °C

To a stirred solution of 2-Sulfamyl-5-amino-pyridine (3 g) in concentrated hydrochloric acid solution (23 ml) was added NaNO2 (1.4 g, 20 mmol) in water (23 ml) while maintaining the temperature between −5° C. and 0° C. After the reaction mixture was stirred at 0° C. for 1.5 hours, SnCl2 (19 g) in concentrated hydrochloric acid solution (25 ml) was added, and the resulting reaction mixture was stirred at 0° C. for 1 hour, then room temperature overnight. The pH of the reaction solution was adjusted to 8 by addition of NaOH (24 g) in water (30 ml), followed by the addition of THF (200 ml). After stirred at room temperature for 30 minutes, the reaction mixture was filtered through Celite®. The aqueous layer was extracted with THF (3×200 ml) and ethyl acetate (2×200 ml). The combined organic layers were dried with sodium sulfate (Na2SO4), and concentrated in vacuo. The product was dissolved in 10% HCl in methanol (50 ml), and the solvent was removed in vacuo to give title compound (2.5 g).

1. temperaturewhile maintaining the temperature between −5° C. and 0° C
2. customthe resulting reaction mixture
3. stirringwas stirred at 0° C. for 1 hour
4. customroom temperature overnight
5. stirringAfter stirred at room temperature for 30 minutes
6. filtrationthe reaction mixture was filtered through Celite®
7. extractionThe aqueous layer was extracted with THF (3×200 ml) and ethyl acetate (2×200 ml)
8. dry with materialThe combined organic layers were dried with sodium sulfate (Na2SO4)
9. concentrationconcentrated in vacuo
10. dissolutionThe product was dissolved in 10% HCl in methanol (50 ml)
11. customthe solvent was removed in vacuo

ORD record

ord-adffb425dabf4fcb82eb50ad56a5772d

Source dataset

uspto-grants-2005_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06878726B2