4-Aminobenzenesulfonic acid(CAS: 121-57-3)

4-Aminobenzenesulfonic acid is a colorless or white crystalline solid with a molecular weight of approximately 189.16 g/mol. It has a solubility of about 7.2 g/100 mL in water at 20°C. The compound is moderately reactive, showing basic properties due to the amino group and acidic properties due to the sulfonic acid group. It is soluble in most organic solvents like methanol, ethanol, and dimethylformamide.

4-Aminobenzenesulfonic acid can be synthesized by the sulfonation of 4-aminobenzoic acid. This process involves treating 4-aminobenzoic acid with fuming sulfuric acid in the presence of a catalyst like pyridine. The reaction is typically carried out at elevated temperatures to improve yield and selectivity. The overall yield can range from 70% to 80% depending on reaction conditions and purification methods.

4-Aminobenzenesulfonic acid is widely used in various industries. It serves as a key intermediate in the production of dyes, pharmaceuticals, and surfactants. Additionally, it is utilized in the synthesis of polymer additives, sensors, and as a precursor in the production of semiconductors. Its versatility makes it a valuable compound in research and industrial applications.

When handling 4-Aminobenzenesulfonic acid, it is crucial to wear appropriate personal protective equipment (PPE) such as gloves, safety goggles, and a lab coat. Store the compound in a dry, well-ventilated area, away from incompatible materials like strong oxidizers. Reactant and product safety data sheets (SDS) should be consulted for detailed handling and disposal guidelines. Fume hoods should be used during operations involving this compound to minimize inhalation risks.