Sodium Hydroxide → 4-[(4-Acetamidophenyl)sulfanyl]-3-nitro-5-sulfamoylbenzoic acid

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Reaction Steps

The starting material is prepared as follows: The mixture of 19.6 g of 4-chloro-3-nitro-5-sulfamoylbenzoic acid, 280 ml of N aqueous sodium hydroxide and 11.8 g of 4-acetamidothiophenol is stirred for 24 hours at room temperature under nitrogen. It is filtered, the filtrate made strongly acidic with concentrated hydrochloric acid, the precipitate formed filtered off and recrystallized from 50% aqueous ethanol, to yield the 4-(4-acetamidophenylmercapto)-3-nitro-5-sulfamoylbenzoic acid, melting at 168°. 8.2 g thereof are added portionwise to the mixture of 16 g of iron powder, 1.7 g of ammonium chloride, 70 ml of water and 0.8 ml of N hydrochloric acid while stirring. After heating it for 4 hours at the steam bath it is filtered hot, the precipitate taken up in 200 ml of N aqueous sodium hydroxide and the solution filtered. The filtrates are acidified with concentrated hydrochloric acid and the precipitate formed recrystallized from 50% aqueous ethanol, to yield the 4-(4-acetamidophenylmercapto)-3-amino-5-sulfamoylbenzoic acid melting at 207°.

Provenance & Evidence