4-Aminophthalic acid
4-Aminophthalic acid (CAS: 5434-21-9, Formula: H2NC6H3-1,2-(CO2H)2) is a versatile aromatic compound with a molecular weight of 181.15 g/mol. It serves as a key building block in organic synthesis, particularly in the creation of dyes, pigments, and complex organic molecules. Its unique structure lends itself to applications in chemical biology and peptide chemistry, enabling the development of novel compounds and research reagents.
- Synonyms
- 2-(CO2H)2H2NC6H3-1,2-(CO2H)2

Chemical Synthesis Intermediate
4-Aminophthalic acid is utilised as a crucial intermediate in the synthesis of various organic compounds, including dyes and pigments. Its functional groups allow for diverse chemical transformations and the construction of more complex molecular architectures.
Research and Development
This compound finds application in academic and industrial research settings, particularly within chemical biology and peptide chemistry. It is used for the exploration of new synthetic routes and the development of novel biologically relevant molecules.
Unnatural Amino Acid Derivatives
As a derivative of unnatural amino acids, 4-Aminophthalic acid can be incorporated into peptide structures to modify their properties. This is valuable for creating specialised peptides for biochemical studies or therapeutic applications.
| Molecular weight | 181.15 |
|---|---|
| Linear formula | H2NC6H3-1,2-(CO2H)2 |
| Assay | 97% |
| Melting point | 344 °C (dec.)(lit.) |

Hazard statements
- H315Causes skin irritation
- H319Causes serious eye irritation
- H335May cause respiratory irritation
Precautionary statements
- P261Avoid breathing dust, fume, gas or vapours
- P305IF IN EYES
| Protective equipment | dust mask type N95 (US), Eyeshields, Gloves |
|---|---|
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | Xi |
| Risk statements (R) | 36/37/38 |
| Safety statements (S) | 26-36 |
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-Aminophthalic acid used for?
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4-Aminophthalic acid is primarily used as an intermediate in chemical synthesis, for research in chemical biology and peptide chemistry, and in the development of unnatural amino acid derivatives.
What is the CAS number and formula for 4-Aminophthalic acid?
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The CAS number is 5434-21-9, and the linear formula is H2NC6H3-1,2-(CO2H)2.
What grade and purity does Tech Serve Solutions supply for 4-Aminophthalic acid?
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Tech Serve Solutions supplies 4-Aminophthalic acid with an assay of 97%. We do not represent this product as USP, BP, or EP grade.
How should 4-Aminophthalic acid be handled?
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4-Aminophthalic acid may cause skin irritation, serious eye irritation, and respiratory irritation. Handle with appropriate personal protective equipment, including a dust mask (type N95 US recommended), eyeshields, and gloves, in a well-ventilated area. Avoid breathing dust. If in eyes, rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
How is 4-Aminophthalic acid packed, shipped, and exported?
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Tech Serve Solutions professionally packages and exports 4-Aminophthalic acid globally, adhering to all relevant shipping regulations for chemical compounds.
How can I request a sample or quote for 4-Aminophthalic acid?
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To request a sample or a quote for 4-Aminophthalic acid, please contact our sales team through the website or by phone.
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