metanilic

Metanilic is a chemical compound, specifically an isomer of sulfanilic acid. Its chemical formula is C6H7NO3S. It is a white crystalline solid and is also known as 3-aminobenzenesulfonic acid or m-aminobenzenesulfonic acid. The 'meta' designation refers to the relative positions of the amino (-NH2) and sulfonic acid (-SO3H) groups on the benzene ring, being at opposite ends (1,3 substitution).

Metanilic acid is a soluble compound in water. It is an important intermediate in the synthesis of various organic compounds, particularly dyes and pharmaceuticals. Its reactivity stems from both the amino group, which can undergo diazotization and coupling reactions, and the sulfonic acid group, which confers water solubility and can be involved in other chemical transformations.

Historically, metanilic acid and its derivatives have found applications in the textile industry as components of azo dyes. In medicinal chemistry, it has served as a building block for certain sulfa drugs, though its direct therapeutic use is limited. The production of metanilic acid typically involves the sulfonation of aniline under specific conditions to favor meta substitution.