5-Methylisoxazole-3-carboxylic acid
Also known as: 5-methyl-1,2-oxazole-3-carboxylic acid, 3-carboxy-5-methylisoxazole, 5-methyl-3-isoxazolecarboxylic acid, 5-Methyl-3-isooxazolecarboxylic acid, 5-Methylisooxazole-3-carboxylic acid
5-Methylisoxazole-3-carboxylic acid (CAS 3405-77-4) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C5H5NO3 and a molecular weight of 127.098 g/mol. Key properties include a melting point of 168 °C, a boiling point of 312.5±22.0 °C at 760 mmHg, a density of 1.3±0.1 g/cm3 and a flash point of 142.8±22.3 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 3405-77-4
- Jingsj CID
- J-17140-4
- Molecular Formula
- C5H5NO3
- Molecular Weight
- 127.098 g/mol
- Category
- Organic Acids
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Melting Point | 168 °C |
|---|---|
| Boiling Point | 312.5±22.0 °C at 760 mmHg |
| Density | 1.3±0.1 g/cm3 |
| Flash Point | 142.8±22.3 °C |
| Exact Mass | 127.026939 |
| PSA | 63.33000 |
| LogP | 0.68 |
| Vapor Pressure | 0.0±0.7 mmHg at 25°C |
| Refractive Index | 1.514 |
Customs & Trade Information
| HS Code | 2934999090 |
|---|---|
| Summary | 2934999090. other heterocyclic compounds. VAT:17.0%. Tax rebate rate:13.0%. . MFN tariff:6.5%. General tariff:20.0% |
Frequently Asked Questions
What is the CAS number of 5-Methylisoxazole-3-carboxylic acid?
The CAS number of 5-Methylisoxazole-3-carboxylic acid is 3405-77-4.
What are the molecular formula and molecular weight of 5-Methylisoxazole-3-carboxylic acid?
5-Methylisoxazole-3-carboxylic acid has molecular formula C5H5NO3 and molecular weight 127.098 g/mol.
What are the upstream and downstream products of 5-Methylisoxazole-3-carboxylic acid?
For 5-Methylisoxazole-3-carboxylic acid, Upstream Products: Ethyl 2,4-dioxovalerate, Ethyl 5-methylisoxazole-3-carboxylate, 2,5-Hexanedione; Downstream Products: (5-Methylisoxazol-3-yl)methanol, 5-Methylisoxazole-3-carbonyl chloride, 5-Methyl-1H-pyrazole-3-carboxylic acid.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "5-Methylisoxazole-3-carboxylic acid (CAS 3405-77-4)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-17140-4 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.