Prefixes sulfonic acids

Sulfur Acids. Organic oxy acids of sulfur, that is, —SO3H, —SO2H, and —SOH, are named sulfonic acid, sulfinic acid, and sulfenic acid, respectively. In subordinate use, the respective prefixes are sulfo-, sulfino, and sulfeno-. The grouping —SO2—O—SO2— or —SO—O—SO is named sulfonic or sulfinic anhydride, respectively. 

This article uses the former nomenclature. Organoperoxysulfonic acids are named by inserting peroxy in the sulfonic acid name, eg, cyclohexaneperoxysulfonic acid [74232-61 ]. For diacids, the prefixes monoperoxy- or diperoxy- are used, eg, monoperoxysuccinic acid and diperoxyisophthahc acid [1786-87 ]. 

Consensus on nomenclature had been reached by the 1890s. Aniline was the parent of its derivatives, though sulfonic acids were considered derivatives of benzene, such as aminobenzenesulfonic acid. The prefix amino- was added to naphthalene and its derivatives. Many trivial names came into use, particularly for aminonaphthalenesulfonic acids, found in both academic and industrial research laboratories. Though IUPAC convention now numbers amino aryl compounds according to the parent hydrocarbon, the earlier system of numbering has often been retained, since some names include the positions of substituents at carbon atoms numbered according to the older systems. 

Benzene rings with substituents other than halo, nitro, sulfonic acid, alkyl, and acyl can be prepared by first synthesizing one of these substituted benzenes and then chemically changing the substituent. The kinds of substituents that can be placed on benzene rings are greatly expanded by reactions of arene dia-zonium salts, nucleophilic aromatic substitution reactions, and reactions involving a benzyne intermediate. The relative positions of two substituents on a benzene ring are indicated either by numbers or by the prefixes ortho, meta, and para. 

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