For chemical professionals engaged in synthesis and product development, a thorough understanding of a chemical's properties is foundational. p-Anisidine-3-sulfonic acid (CAS 13244-33-2) is a compound widely used as an intermediate in the dye industry. Knowing its physical and chemical characteristics is key to its effective application and safe handling. This article outlines the critical properties of p-Anisidine-3-sulfonic acid, often sought by manufacturers and researchers.

Chemical Identity and Formula
p-Anisidine-3-sulfonic acid, also known by synonyms such as 4-methoxy-2-sulfoaniline or 2-amino-5-methoxybenzenesulfonic acid, has the molecular formula C7H9NO4S. This formula indicates a molecule comprising seven carbon atoms, nine hydrogen atoms, one nitrogen atom, four oxygen atoms, and one sulfur atom. Its molecular weight is approximately 203.22 g/mol.

Physical Appearance and Form
The typical appearance of p-Anisidine-3-sulfonic acid is as a powder, ranging in color from white to gray and sometimes brown. This color variation can depend on the manufacturing process and purity levels. For applications where color consistency is paramount, such as in dye synthesis, sourcing from manufacturers who provide consistent color batches is important.

Key Physical and Chemical Properties
While detailed technical specifications can vary slightly between suppliers, common properties cited for p-Anisidine-3-sulfonic acid include:

  • Melting Point: The melting point is reported to be in the range of 314-318°C. This high melting point indicates a stable crystalline structure, typical for many sulfonic acid derivatives.
  • Density: An estimated density is around 1.4540 g/cm³.
  • Refractive Index: An estimated refractive index is 1.6370.
  • Solubility: While not always explicitly stated, sulfonic acid groups generally impart some degree of water solubility, which is beneficial for its use in aqueous dye baths.

Safety and Handling Information
According to GHS classifications, p-Anisidine-3-sulfonic acid may be classified with hazard statements such as H317 (May cause an allergic skin reaction) and H319 (Causes serious eye irritation). Standard precautionary statements include wearing protective gloves, eye protection, and ensuring adequate ventilation. For detailed safety information, always refer to the Material Safety Data Sheet (MSDS) provided by the supplier.

Sourcing High-Quality Material
For manufacturers and researchers looking to buy p-Anisidine-3-sulfonic acid, it is essential to partner with reputable suppliers who provide accurate property data and high-purity products. NINGBO INNO PHARMCHEM CO.,LTD. offers this critical intermediate and can provide detailed specifications and support. Contact us for your requirements and to learn about competitive pricing and reliable supply options.