C07C309/57 - CPC Classification

Sulfonic acids; Halides, esters, or anhydrides thereof; Sulfonic acids having sulfo groups bound to carbon atoms of six-membered aromatic rings of a carbon skeleton containing carboxyl groups bound to the carbon skeleton

• C07C309/58 » Carboxylic acid groups or esters thereof 44
• C07C309/59 » Nitrogen analogues of carboxyl groups 23
• C07C309/60 » the carbon skeleton being further substituted by singly-bound oxygen atoms 23
• C07C309/61 » the carbon skeleton being further substituted by nitrogen atoms, not being part of nitro or nitroso groups 8