Sulfonamide (chemistry)

File:Sulfonamide-group.png

The structure of the sulfonamide group

In chemistry, the sulfonamide functional group is -S(=O)₂-NH₂, a sulfone group connected to an amine group.

A sulfonamide (compound) is a compound that contains this group. The general formula is RSO₂NH₂, where R is some organic group. For example, "methanesulfonamide" is CH₃SO₂NH₂. Any sulfonamide can be considered as derived from a sulfonic acid by replacing a hydroxyl group with an amine group.

In medicine, the term "sulfonamide" is sometimes used as a synonym for sulfa drug, a derivative or variation of sulfanilamide.

Organic synthesis

Sulfonamides can be prepared in the laboratory in many ways:

• by reaction of sulfonyl chlorides with amines for example in the synthesis of sulfonylmethylamide . A readily available sulfonyl chloride source is tosyl chloride
• In one study symmetric sulfonamides are prepared directly from amines and sulfur dioxide gas :

Sulfonamide synthesis from aniline and sulfur dioxide

In this example the reactant is aniline and the catalysts are triethylamine and iodine. Sulfur dioxide is believed to be activated through a series of intermediates: Et₃N-I⁺-I^-, Et₃N-I⁺-I₃^- and Et₃N⁺-SO₂^-.

See also

• Sulfonamide (medicine)
• Sulfamic acid
• Sulfamide

References

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