C6H6O3S

C6H6O3S is the chemical formula for benzenesulfonic acid, an aromatic sulfonic acid consisting of a benzene ring bearing a sulfonic acid group (-SO3H). It is commonly referred to as benzenesulfonic acid (British spelling: benzenesulphonic acid). The molecule is a monoprotic strong acid; in aqueous solution it dissociates to yield the benzenesulfonate anion.

Benzenesulfonic acid is a white, crystalline solid at room temperature with a relatively high melting point. It is soluble in water and in many polar organic solvents and is considered to be a strong, non-volatile acid suitable for various chemical applications.

Preparation and uses: It is produced by the sulfonation of benzene using sulfuric acid or oleum. The compound serves as a versatile building block in organic synthesis: it acts as a strong acid catalyst in esterifications and other reactions, and serves as an intermediate to make sulfonyl chlorides, sulfonate esters, dyes, and pharmaceutical intermediates. Derivatives include benzenesulfonyl chlorides and various sulfonate esters.

Safety and handling: Benzenesulfonic acid is corrosive and can cause severe eye and skin irritation. It should be handled with appropriate personal protective equipment, and waste should be disposed of according to applicable regulations.