4-Hydrazinobenzene-1-sulfonamide hydrochloride

63-74-1

17852-52-7

The general procedure for the synthesis of p-hydrazinylbenzenesulfonamide hydrochloride from crystalline sulfanilamide was as follows: firstly, 4'-methylacetophenone was reacted with succinic anhydride in the presence of diisopropanolamine (LDA) and tetrahydrofuran (THF) for 1 hr at -78 °C to afford p-tolyl-4,6-dioxohexanoic acid in 66% yield and the product was a white solid. Subsequently, the sulfonamide was reacted with sodium nitrite (NaNO2) and concentrated hydrochloric acid for 30 min at 0-4 °C, followed by the addition of tin(II) chloride (SnCl2), and the reaction was continued for 4 h at 0 °C to produce 4-sulfonylaminophenylhydrazine hydrochloride in 55% yield, the product being a pale yellow solid. Finally, p-tolyl-4,6-dioxohexanoic acid was reacted with 4-sulfonylaminophenylhydrazine hydrochloride in a methanolic solution of triethanolamine (TEA) at room temperature for 16 h to give compound 30c, 3-[1-{p-(p-(sulfonylamino)phenyl}-5-p-tolyl-1H-pyrazol-3-yl]propanoic acid in 76% yield and the product was a yellow solid.