In the realm of specialty chemicals, intermediates play a pivotal role, bridging raw materials to finished products. One such crucial intermediate is 2-Methyl-5-nitrobenzenesulfonic Acid, more commonly known by its CAS number 121-03-9 or as 4-Nitrotoluene-2-sulfonic Acid. This compound is highly valued for its reactive functional groups and is indispensable in the manufacturing of fluorescent whitening agents and a broad spectrum of dyes. As a dedicated supplier and manufacturer from China, we offer insights into its chemical properties and diverse applications for your consideration.

Understanding the Chemistry: Properties of CAS 121-03-9

2-Methyl-5-nitrobenzenesulfonic Acid (C7H7NO5S) is characterized by its sulfonic acid group (-SO3H) and a nitro group (-NO2) attached to a toluene backbone. This combination imbues the molecule with specific chemical characteristics:

  • Acidity: The sulfonic acid group makes it a strong acid, readily forming salts.
  • Reactivity of the Nitro Group: The nitro group can be reduced to an amino group (-NH2), a fundamental transformation in the synthesis of many organic compounds, including dyes. This reduction step is often a precursor to azo coupling reactions.
  • Water Solubility: The sulfonic acid moiety generally confers good water solubility, which is advantageous in many industrial processes, particularly in aqueous dyeing baths.
  • Physical Appearance: Typically appears as a very dark brown solid. Its melting point is around 125-131°C.

These properties make it a versatile building block for chemists looking to synthesize complex molecules. For businesses intending to buy this intermediate, understanding these chemical behaviors is key to optimizing their own synthesis routes.

Diverse Applications Driving Demand

The primary applications driving the demand for 2-Methyl-5-nitrobenzenesulfonic Acid are:

  1. Fluorescent Whitening Agents (FWAs): It serves as a key precursor for stilbene-based FWAs, such as 4,4'-dinitrostilbene-2,2'-disulfonic acid. These agents are crucial for enhancing the perceived whiteness and brightness in textiles, paper, and detergents.
  2. Dye Synthesis: The compound is a vital intermediate in the production of various types of dyes, including direct dyes, acid dyes, and reactive dyes. Its ability to undergo transformation into an amine is fundamental for creating colored compounds.
  3. Organic Synthesis: Beyond dyes and FWAs, it finds use in other specialty organic synthesis pathways where its unique functional groups are leveraged.

As a reliable manufacturer and supplier from China, we ensure that our 2-Methyl-5-nitrobenzenesulfonic Acid (CAS 121-03-9) meets the high purity and performance standards required for these applications. If your company is looking to buy this essential chemical intermediate, we offer competitive pricing and consistent supply. Contact us to learn more about how we can meet your specific requirements.