Isophthalic acid
Also known as: 1,3-Benzenedicarboxylic acid, m-Phthalic acid, Benzene-1,3-dicarboxylic acid, IPA
Isophthalic acid (CAS 121-91-5) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C8H6O4 and a molecular weight of 166.131 g/mol. Key properties include a melting point of 341-343 °C(lit.), a boiling point of 412.3±28.0 °C at 760 mmHg, a density of 1.5±0.1 g/cm3 and a flash point of 217.3±20.5 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 121-91-5
- Jingsj CID
- J-33214-9
- Molecular Formula
- C8H6O4
- Molecular Weight
- 166.131 g/mol
- Category
- Organic Acids
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Melting Point | 341-343 °C(lit.) |
|---|---|
| Boiling Point | 412.3±28.0 °C at 760 mmHg |
| Density | 1.5±0.1 g/cm3 |
| Flash Point | 217.3±20.5 °C |
| Exact Mass | 166.026611 |
| PSA | 74.60000 |
| LogP | 1.66 |
| Vapor Pressure | 0.0±1.0 mmHg at 25°C |
| Refractive Index | 1.618 |
| Stability | Stable. Incompatible with strong oxidizing agents, strong bases. |
| Additional Property | 0.01 g/100 mL (25 ºC) |
Customs & Trade Information
| HS Code | 2917391000 |
|---|---|
| Summary | 2917391000 isophthalic acid。Supervision conditions:None。VAT:17.0%。Tax rebate rate:9.0%。Lowest tariff:6.5%。General tariff:30.0% |
Frequently Asked Questions
What is the CAS number of Isophthalic acid?
The CAS number of Isophthalic acid is 121-91-5.
What are the molecular formula and molecular weight of Isophthalic acid?
Isophthalic acid has molecular formula C8H6O4 and molecular weight 166.131 g/mol.
What are the upstream and downstream products of Isophthalic acid?
For Isophthalic acid, Upstream Products: m-Xylene, 3-Methylbenzoic acid, Isophthalaldehyde; Downstream Products: 3,5-Bis(trifluoromethyl)bromobenzene, 1,3-Dibenzoylbenzene, 1-Chloro-3,5-bis(trifluoromethyl)benzene.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "Isophthalic acid (CAS 121-91-5)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-33214-9 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.