3-Butynoic acid
3-丁炔酸
Also known as: 2-Ethynylacetic acid, But-3-ynoic acid, Ethynylacetic acid, 3-Bytynoic acid
3-Butynoic acid (CAS 2345-51-9) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C4H4O2 and a molecular weight of 84.07 g/mol. It is also known as 2-Ethynylacetic acid, But-3-ynoic acid and Ethynylacetic acid. Key properties include a melting point of 188-195ºC, a boiling point of 194.9±23.0 °C at 760 mmHg, a density of 1.2±0.1 g/cm3 and a flash point of 82.6±17.3 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 2345-51-9
- Jingsj CID
- J-1959288-2
- Molecular Formula
- C4H4O2
- Chinese Name
- 3-丁炔酸
- Molecular Weight
- 84.07 g/mol
- Category
- Organic Acids
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Melting Point | 188-195ºC |
|---|---|
| Boiling Point | 194.9±23.0 °C at 760 mmHg |
| Density | 1.2±0.1 g/cm3 |
| Flash Point | 82.6±17.3 °C |
Frequently Asked Questions
What is the CAS number of 3-Butynoic acid?
The CAS number of 3-Butynoic acid is 2345-51-9.
What are the molecular formula and molecular weight of 3-Butynoic acid?
3-Butynoic acid has molecular formula C4H4O2 and molecular weight 84.07 g/mol.
Data compiled from public chemical databases and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "3-Butynoic acid (CAS 2345-51-9)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1959288-2 (accessed 2026-10-22).
Data for reference only; verify specifications, grades and regulatory status with suppliers before purchase.