
Aniline 4 Sulfonic Acid is also known as 4-aminobenzenesulfonic acid or 4-sulfanilic acid. It is an aromatic organic compound with the molecular formula C₆H₇NO₃S. It belongs to the aminobenzenesulfonic acid family and is an aniline derivative in which the amino group and sulfonic acid group are positioned at the para position of the benzene ring. Aniline 4 Sulfonic Acid is an off-white to white crystalline solid that exists predominantly as a zwitterion, a structural feature that contributes to its relatively high melting point and thermal stability compared to related aromatic compounds such as aniline and benzenesulfonic acid. It is an important aromatic intermediate in organic chemistry and is widely known for its stable chemical structure.

CAS No.: 121-57-3
Synonyms: 4-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid, Sulfanilic acid, 4-sulfanilic acid
| Physical Properties | |
| Chemical formula | C6H7NO3S |
| IUPAC Name | 4-aminobenzenesulfonic acid |
| Molecular weight | 173.19Â g/mol |
| Solubility | Soluble in water |
| Appearance | White or grayish-white powder |
| Density | 1.485 g/cm3 at 25 °C |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | grayish-white |
| Physical State | Solid |
| Melting Point | 288 °C |
| Ph | 2.5 |
| Odor | Odorless |
| Pictograms : | ![]() |
| Hazard Statements : | H315: Causes skin irritation. H317: May cause an allergic skin reaction. H319: Causes serious eye irritation. |
| Precautionary statements : | P261: Avoid breathing dust/fume/gas/mist/vapours/spray. P264: Wash thoroughly after handling. P270: Do not eat, drink or smoke when using this product. P310: Immediately call a POISON CENTER/doctor. P330: Rinse mouth. P304+P340: IF INHALED: Remove person to fresh air and keep comfortable for breathing. |
Aniline 4 Sulfonic Acid is also known as 4-aminobenzenesulfonic acid or 4-sulfanilic acid. It is an aromatic organic compound with the molecular formula C₆H₇NO₃S. It belongs to the aminobenzenesulfonic acid family and is an aniline derivative in which the amino group and sulfonic acid group are positioned at the para position of the benzene ring. Aniline 4 Sulfonic Acid is an off-white to white crystalline solid that exists predominantly as a zwitterion, a structural feature that contributes to its relatively high melting point and thermal stability compared to related aromatic compounds such as aniline and benzenesulfonic acid. It is an important aromatic intermediate in organic chemistry and is widely known for its stable chemical structure.

CAS No.: 121-57-3
Synonyms: 4-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid, Sulfanilic acid, 4-sulfanilic acid
| Physical Properties | |
| Chemical formula | C6H7NO3S |
| IUPAC Name | 4-aminobenzenesulfonic acid |
| Molecular weight | 173.19Â g/mol |
| Solubility | Soluble in water |
| Appearance | White or grayish-white powder |
| Density | 1.485 g/cm3 at 25 °C |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | grayish-white |
| Physical State | Solid |
| Melting Point | 288 °C |
| Ph | 2.5 |
| Odor | Odorless |
| Pictograms : | ![]() |
| Hazard Statements : | H315: Causes skin irritation. H317: May cause an allergic skin reaction. H319: Causes serious eye irritation. |
| Precautionary statements : | P261: Avoid breathing dust/fume/gas/mist/vapours/spray. P264: Wash thoroughly after handling. P270: Do not eat, drink or smoke when using this product. P310: Immediately call a POISON CENTER/doctor. P330: Rinse mouth. P304+P340: IF INHALED: Remove person to fresh air and keep comfortable for breathing. |
Aniline 4 Sulfonic Acid is mainly employed as an intermediate in the manufacture of azo dyes, as a reagent for nitrate and nitrite determination, and as a building block in organic synthesis and laboratory research.
Aniline 4 Sulfonic Acid is also known as 4-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid or 4-sulfanilic acid.
Aniline 4 Sulfonic Acid is an amphoteric compound because it contains both an amino group and a sulfonic acid group. In the solid state, it predominantly exists as a zwitterion.
Aniline 4 Sulfonic Acid appears as an off-white to white crystalline powder or grayish white crystals and has relatively high melting point because of its zwitterionic structure.
Aniline 4 Sulfonic Acid is commonly prepared by sulfonating aniline with concentrated sulfuric acid. It is followed by molecular rearrangement to produce the para-substituted product.
Aniline 4 Sulfonic Acid is slightly soluble in cold water but becomes more soluble in hot water and in alkaline solutions due to the formation of sulfonate salts.Â