Benzenesulfonyl chloride

Benzenesulfonyl chloride (CAS 98-09-9), also known as phenylsulfonyl chloride, is a reactive sulfonylating agent used across pharmaceutical synthesis, dye manufacturing, and specialty chemical production. It introduces sulfonyl groups into organic molecules, enabling the construction of intermediates that would otherwise require multiple synthetic steps. In pharmaceutical manufacturing, it serves as a key building block.

This chemical is essential for synthesizing sulfonamide drugs, protecting groups, and active pharmaceutical intermediates requiring controlled sulfonylation. Dye and pigment producers use it to manufacture azo dyes. These reactive dyes are widely applied in textile and leather finishing. Water treatment chemical formulators incorporate sulfonyl chloride-derived compounds as biocidal actives targeting microbial control.

These applications are critical for industrial water systems. Paper processing operations also draw on sulfonyl-based chemistry for surface treatment agents that improve wet strength and resistance properties. The product is supplied as a colorless to pale yellow liquid in standard drum and IBC packaging suited to bulk industrial procurement. It is available in technical grade and high-purity grades.

These grades meet pharmaceutical intermediate specifications, with purity typically confirmed by GC analysis. Buyers should confirm moisture-controlled packaging requirements with suppliers for safety. The product is sensitive to hydrolysis during storage and transit. Proper handling ensures the material maintains its chemical integrity for use in sensitive manufacturing and synthesis processes.