Hydrochloric Acid → Sulfanilamide

The 4-nitrobenzenesulfonamide obtained (5.9 g) was dissolved in methanol (100 ml), and after an addition of conc. hydrochloric acid, reduced iron (4.2 g) was added and the mixture stirred at room temperature for 2 hours. After filtration, methanol was evaporated under a reduced pressure, the residue was made basic with an addition of 4 N sodium hydroxide, and the mixture of the desired product and iron oxide precipitated was collected by filtration. The mixture was dissolved in acetone (200 ml), filtered to remove iron oxide, and the solvent was evaporated under a reduced pressure to obtain 4-aminobenzenesulfonamide (3.7 g) (m.p. 164° C.-165.5° C.).

1. additionwas added
2. filtrationAfter filtration, methanol
3. customwas evaporated under a reduced pressure
4. additionthe residue was made basic with an addition of 4 N sodium hydroxide
5. additionthe mixture of the desired product and iron oxide
6. customprecipitated
7. filtrationwas collected by filtration
8. dissolutionThe mixture was dissolved in acetone (200 ml)
9. filtrationfiltered
10. customto remove iron oxide
11. customthe solvent was evaporated under a reduced pressure

ORD record

ord-b139eafbb9654093aaff6bf7d9133f05

Source dataset

uspto-grants-1993_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05205855