benzenesulfonic

Benzenesulfonic acid is an organosulfur compound with the formula C6H5SO3H. It consists of a benzene ring bearing a sulfonic acid group (-SO3H). The molecule is typically a colorless solid that is highly soluble in water and many polar organic solvents. It is a strong acid, stronger than carboxylic acids, and forms benzenesulfonate salts upon neutralization.

Preparation and availability: It is produced by sulfonation of benzene with sulfuric acid or oleum, yielding benzenesulfonic acid that can be isolated by crystallization. It can also be obtained from sulfonyl chloride derivatives or converted from related sulfonating reagents.

Reactions and derivatives: As a sulfonic acid, it readily forms salts (e.g., sodium benzenesulfonate). It can be converted to sulfonyl chlorides (such as benzenesulfonyl chloride) using chlorinating reagents like thionyl chloride, enabling the synthesis of sulfonamides. The sulfonic acid group is a versatile functional handle in organic synthesis and in the formation of various sulfonate derivatives.

Applications: Benzenesulfonic acid serves as a useful building block in organic synthesis, particularly for preparing sulfonamide compounds and related reagents. Its salts find use in detergents, chromatography, and as reagents or counterions in pharmaceutical and industrial chemistry. Its derivatives are employed in dye chemistry and other specialty syntheses.

Safety: The compound is corrosive and can cause irritation to skin, eyes, and the respiratory tract. It should be handled with appropriate protective equipment, and kept away from bases and incompatible materials.