4-Bromo-1-butyne
Also known as: 1-Bromo-3-butyne, 3-Butynyl bromide, 4-Bromobut-1-yne, Homopropargyl bromide
4-Bromo-1-butyne (CAS 38771-21-0) is a compound in the Aliphatic Hydrocarbons category listed in the Jingsj chemical database. It has the molecular formula C4H5Br and a molecular weight of 132.986 g/mol. Key properties include a boiling point of 118.3±23.0 °C at 760 mmHg, a density of 1.5±0.1 g/cm3 and a flash point of 32.3±17.0 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 38771-21-0
- Jingsj CID
- J-1624025-8
- Molecular Formula
- C4H5Br
- Molecular Weight
- 132.986 g/mol
- Category
- Aliphatic Hydrocarbons
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Boiling Point | 118.3±23.0 °C at 760 mmHg |
|---|---|
| Density | 1.5±0.1 g/cm3 |
| Flash Point | 32.3±17.0 °C |
| Exact Mass | 131.957458 |
| LogP | 1.72 |
| Vapor Pressure | 20.0±0.2 mmHg at 25°C |
| Refractive Index | 1.483 |
| Storage Conditions | 2~8℃ |
Customs & Trade Information
| HS Code | 2903399090 |
|---|---|
| Summary | 2903399090. brominated,fluorinated or iodinated derivatives of acyclic hydrocarbons. VAT:17.0%. Tax rebate rate:13.0%. . MFN tariff:5.5%. General tariff:30.0% |
Frequently Asked Questions
What is the CAS number of 4-Bromo-1-butyne?
The CAS number of 4-Bromo-1-butyne is 38771-21-0.
What are the molecular formula and molecular weight of 4-Bromo-1-butyne?
4-Bromo-1-butyne has molecular formula C4H5Br and molecular weight 132.986 g/mol.
What are the upstream and downstream products of 4-Bromo-1-butyne?
For 4-Bromo-1-butyne, Upstream Products: 3-Butyn-1-ol, but-3-ynyl 4-methylbenzenesulfonate; Downstream Products: 6,8-Dimethoxy-4-methylquinoline, 4-Bromo-1-butene, 4-Cyano-1-butyne.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "4-Bromo-1-butyne (CAS 38771-21-0)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1624025-8 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.