Ammonium Hydroxide → 2-Amino-5-nitrobenzenesulfonamide

Temperature

118 °C

2-Chloro-5-nitro-benzenesulfonamide (1.95 kg, 8.30 mol), ammonium carbonate (1.983 kg, 20.64 mol), and copper (II) sulfate (394 g, 2.47 mol) were charged to an autoclave and diluted with a 30% aqueous ammonium hydroxide solution (11.7 L, 330 mol). The mixture was heated at 118° C. for 3 days and was then cooled to 23° C. The mixture was filtered and the solids were then washed with water (20 L). This solid was dissolved in hot methanol (20 mL/g), and the mixture was filtered to remove undissolved solids. The filtrate was stored at 4° C. overnight, and the resulting solid product was then filtered. The filtrate was partially concentrated by vacuum distillation and, when the concentrate was cooled to 23° C., the solid product was then filtered off. The two crops of solid were combined and further dried in vacuo at 45° C. to afford the desired product, 2-amino-5-nitro-benzenesulfonamide (1.10 kg, 5.06 mol, 61%), as a solid. 1H NMR (400 MHz, DMSO-d6) δ: 6.89 (d, J=9.3 Hz, 1H), 7.12 (bs, 2H), 7.57 (bs, 2H), 8.07 (dd, J1=9.0 Hz, J2=2.6 Hz, 1H), 8.43 (d, J=3.0 Hz, 1H).

1. temperaturewas then cooled to 23° C
2. filtrationThe mixture was filtered
3. washthe solids were then washed with water (20 L)
4. dissolutionThis solid was dissolved in hot methanol (20 mL/g)
5. filtrationthe mixture was filtered
6. customto remove undissolved solids
7. filtrationthe resulting solid product was then filtered
8. concentrationThe filtrate was partially concentrated by vacuum distillation and, when the concentrate
9. temperaturewas cooled to 23° C.
10. filtrationthe solid product was then filtered off
11. customfurther dried in vacuo at 45° C.

ORD record

ord-b095dc514a5d401eabde3720d6f7f0f4

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08101800B2