Methanesulfonic Acid → 2,5-Diamino-benzenesulfonamide methanesulfonate

Participants

Reaction Conditions

Reaction Steps

2-Amino-5-nitrobenzenesulfonamide (prepared as described in Example 1b, 100.00 g, 0.460 mol) and 5% palladium on carbon (wet, 5.00 g) were suspended in ethanol (2 L) and water (100 mL). Methanesulfonic acid (33 mL, 0.51 mol) was added, and the resulting mixture was heated to 55° C. and stirred under atmospheric hydrogen for 8 h. The mixture was filtered and the filtrate was concentrated in vacuo to a volume of about 450 mL. To the concentrate was added acetonitrile (1 L) and resulting mixture was stirred at 25° C. overnight. The suspension was filtered to afford the desired product, 2,5-diamino-benzenesulfonamide methanesulfonate (122.36 g, 0.432 mol, 93.8%) as a purple solid.

Provenance & Evidence