3-Mercaptobenzoic acid
3-Mercaptobenzoic acid (CAS: 4869-59-4), with the molecular formula HSC6H4CO2H and a molecular weight of 154.19 g/mol, is an important organic building block. This thiol derivative is valuable in chemical synthesis, particularly for introducing mercapto and carboxylic acid functionalities. It serves as a key intermediate in the production of various organic compounds and specialty chemicals, owing to its reactive functional groups.

Organic Synthesis Intermediate
3-Mercaptobenzoic acid is widely employed as a versatile intermediate in organic synthesis. Its dual functionality allows for diverse chemical transformations in the development of pharmaceuticals, agrochemicals, and advanced materials.
Building Block for Specialty Chemicals
This compound acts as a foundational building block for the creation of sulphur-containing organic molecules and complex structures. It is utilised in research and development for novel chemical entities.
Reagent in Material Science
The presence of both thiol and carboxylic acid groups makes 3-Mercaptobenzoic acid useful in surface modification and the synthesis of functional polymers. It can participate in reactions leading to self-assembled monolayers and functionalised surfaces.
| Molecular weight | 154.19 |
|---|---|
| Linear formula | HSC6H4CO2H |
| Assay | 95% |
| Melting point | 144-147 °C(lit.) |


Hazard statements
- H315Causes skin irritation
- H318Causes serious eye damage
- H335May cause respiratory irritation
Precautionary statements
- P261Avoid breathing dust, fume, gas or vapours
- P280Wear protective gloves, clothing and eye/face protection
- P305IF IN EYES
| Protective equipment | dust mask type N95 (US), Eyeshields, Gloves |
|---|---|
| Transport (UN / ADR) | UN 3335 |
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | Xi |
| Risk statements (R) | 37/38-41 |
| Safety statements (S) | 26-36/37/39 |
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 3-Mercaptobenzoic acid used for?
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3-Mercaptobenzoic acid is primarily used as an intermediate in organic synthesis and as a building block for specialty chemicals and in material science applications due to its reactive thiol and carboxylic acid groups.
What is the CAS number and molecular formula for 3-Mercaptobenzoic acid?
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The CAS number for 3-Mercaptobenzoic acid is 4869-59-4, and its molecular formula is HSC6H4CO2H.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies 3-Mercaptobenzoic acid with an assay of 95%. This is a technical grade material, and TSS does not represent it as USP, BP, or EP grade.
How should 3-Mercaptobenzoic acid be handled safely?
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3-Mercaptobenzoic acid is classified as Dangerous. It can cause skin irritation (H315), serious eye damage (H318), and respiratory irritation (H335). Appropriate personal protective equipment, including a dust mask (type N95), eyeshields, and gloves, must be worn. Handle in a well-ventilated area and avoid breathing dust.
How is 3-Mercaptobenzoic acid shipped and exported?
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3-Mercaptobenzoic acid is shipped and exported in compliance with relevant regulations. It is classified under UN 3335. Please contact TSS for specific export documentation and shipping details.
How can I request a quote or sample of 3-Mercaptobenzoic acid?
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To request a quote or a sample of 3-Mercaptobenzoic acid, please visit the Tech Serve Solutions website or contact our sales department directly with your inquiry.
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