4-Hydrazinobenzenesulfonic Acid CAS 98-71-5

FAQ - Technical & Supply Chain

• Q:

  What is 4-Hydrazinobenzenesulfonic Acid CAS 98-71-5?

  A: 4-Hydrazinobenzenesulfonic Acid is a bifunctional sulfonic acid derivative identified by CAS 98-71-5 and molecular formula C₆H₈N₂O₃S. It is also called 4-hydrazinylbenzenesulfonic acid, phenylhydrazine-4-sulfonic acid, or p-sulfophenylhydrazine. The molecule combines a hydrazine group with a sulfonic acid group, making it useful as a reactive intermediate.
• Q:

  What is 4-Hydrazinobenzenesulfonic Acid mainly used for?

  A: It is mainly used as a dye and pigment intermediate, especially in the preparation of pyrazolone colorants such as Acid Yellow 23 / Tartrazine and related dyes. It can also be converted to 1-(4-sulfophenyl)-3-methyl-5-pyrazolone or used in routes to optical brightener Tinopal WG. Some applications describe it as an ice-color or azoic dye resist agent.
• Q:

  What grades and typical properties should be confirmed?

  A: Catalog grades commonly include approximately 98% material, while some industrial offers state higher purity or dye-intermediate grade. Typical physical properties are a white to light-yellow crystalline powder, a melting point around 285-287 °C with decomposition, and greater solubility in boiling water than cold water. Confirm assay, hydrate or free-acid form, moisture, and process-specific impurities for the intended synthesis.
• Q:

  How should 4-Hydrazinobenzenesulfonic Acid be stored and handled?

  A: Store in tightly closed, compatible containers in a cool, dry, ventilated area away from oxidizers, strong bases, and incompatible materials. Avoid dust generation and unnecessary moisture contact. Because it is a hydrazine derivative, use appropriate PPE and follow the applicable handling and disposal requirements for the intended scale.