4-Aminotoluene-3-sulfonic acid
4-Aminotoluene-3-sulfonic acid (CAS: 88-44-8), with the molecular formula H2NC6H3(CH3)SO3H and a molecular weight of 187.22 g/mol, is an organic compound primarily utilised as a chemical intermediate. It serves as a valuable building block in organic synthesis, particularly in the creation of specialised molecules such as azobenzene derivatives. Its applications extend to analytical chemistry, where it can be employed in solid-phase extraction studies for the enrichment of related compounds.
- IUPAC
- 2-Amino-5-methylbenzenesulfonic acid,4-Methylaniline-2-sulfonic acid
- Synonyms
- 2-Amino-5-methylbenzenesulfonic acid4-Methylaniline-2-sulfonic acid

Intermediate in Azobenzene Synthesis
4-Aminotoluene-3-sulfonic acid is used in the synthesis of various azobenzene derivatives, contributing to the production of dyes and other complex organic molecules.
Analytical Chemistry Applications
This compound has been utilised in studies investigating solid-phase extraction techniques, specifically for the enrichment of aminobenzoic acids and aminotoluenesulfonic acids using graphitized carbon black.
Organic Building Block
As a versatile organic building block, it is employed in chemical synthesis for constructing more complex molecular architectures.
| Molecular weight | 187.22 |
|---|---|
| Linear formula | H2NC6H3(CH3)SO3H |
| Assay | 99% |
| Solubility | water: soluble6 g/L at 20 °C |
| Application | 4-Aminotoluene-3-sulfonic acid was used to investigate the enrichment of aminobenzoic acids and aminotoluenesulfonic acids using graphitized carbon black (GCB) by solid-phase extraction1. It was also used in the synthesis of azobenzene derivatives2. |

Hazard statements
- H314Causes severe skin burns and eye damage
Precautionary statements
- P280Wear protective gloves, clothing and eye/face protection
- P305IF IN EYES
- P310Immediately call a POISON CENTER or doctor
| Protective equipment | dust mask type N95 (US), Eyeshields, Gloves |
|---|---|
| Transport (UN / ADR) | UN 2585 8/PG 3 |
| Water hazard class (WGK, DE) | 2 |
| Hazard codes (EU) | Xi |
| Risk statements (R) | 36 |
| Safety statements (S) | 26 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is 4-Aminotoluene-3-sulfonic acid used for?
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4-Aminotoluene-3-sulfonic acid is used as a chemical intermediate in the synthesis of azobenzene derivatives and in analytical chemistry for solid-phase extraction studies.
What are the CAS number and chemical formula for 4-Aminotoluene-3-sulfonic acid?
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The CAS number for 4-Aminotoluene-3-sulfonic acid is 88-44-8, and its chemical formula is H2NC6H3(CH3)SO3H.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies 4-Aminotoluene-3-sulfonic acid with an assay of 99%. We do not represent this product as USP, BP, or EP grade.
How should 4-Aminotoluene-3-sulfonic acid be handled safely?
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4-Aminotoluene-3-sulfonic acid is classified as dangerous. It causes severe skin burns and eye damage (H314). Handle with appropriate personal protective equipment, including a dust mask (N95), eyeshields, and gloves. Ensure good ventilation and follow specific safety precautions outlined in the Safety Data Sheet.
Is 4-Aminotoluene-3-sulfonic acid a controlled substance?
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The provided data does not indicate that 4-Aminotoluene-3-sulfonic acid is a controlled substance.
How can I request a sample or quote for 4-Aminotoluene-3-sulfonic acid?
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To request a sample or a quote for 4-Aminotoluene-3-sulfonic acid, please contact the Tech Serve Solutions sales team through our website or by phone.
How is 4-Aminotoluene-3-sulfonic acid shipped?
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4-Aminotoluene-3-sulfonic acid is shipped internationally by Tech Serve Solutions according to relevant transport regulations, identified as UN 2585, Class 8, Packing Group III.
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