3-Methylbut-1-ene

Also known as: 1-Butene, 3-methyl-, 1-Butene,3-methyl, 1-isopropylethylene, 2-Methyl-3-butene, 3-methyl-but-1-ene, 3-methylbut-1-ene, EINECS 209-249-1, ISOPROPYLETHYLENE, Isopentene, MFCD00008937, Methylethylethylene, Vinylisopropyl

3-Methylbut-1-ene (CAS 563-45-1) is a compound in the Aliphatic Hydrocarbons category listed in the Jingsj chemical database. It has the molecular formula C5H10 and a molecular weight of 70.133 g/mol. Key properties include a melting point of -168 °C, a boiling point of 20.1±0.0 °C at 760 mmHg, a density of 0.7±0.1 g/cm3 and a flash point of -56.7±0.0 °C. It is classified under GHS with signal word Danger and hazard statements H224, H304 and H315 — Causes skin irritation. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.

CAS No.: 563-45-1
Jingsj CID: J-11124-9
Molecular Formula: C₅H₁₀
Molecular Weight: 70.133 g/mol
Category: Aliphatic Hydrocarbons
Last updated: 8/21/2026

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Physicochemical Properties

Melting Point	-168 °C
Boiling Point	20.1±0.0 °C at 760 mmHg
Density	0.7±0.1 g/cm3
Flash Point	-56.7±0.0 °C
Exact Mass	70.078247
LogP	2.72
Vapor Pressure	905.3±0.0 mmHg at 25°C
Refractive Index	1.384

GHS Safety & Compliance

Flammable / Irritant / Health HazardSignal word: Danger

H224
H304
H315 — Causes skin irritation
H319 — Causes serious eye irritation
H335 — May cause respiratory irritation

Frequently Asked Questions

What is the CAS number of 3-Methylbut-1-ene?

The CAS number of 3-Methylbut-1-ene is 563-45-1.

What are the molecular formula and molecular weight of 3-Methylbut-1-ene?

3-Methylbut-1-ene has molecular formula C5H10 and molecular weight 70.133 g/mol.

Is 3-Methylbut-1-ene hazardous?

3-Methylbut-1-ene has GHS signal word Danger and hazard statements H224; H304; H315 — Causes skin irritation.

Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.

Last updated: 8/21/2026

How to cite: Jingsj. "3-Methylbut-1-ene (CAS 563-45-1)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-11124-9 (accessed 2026-11-07).

Data for reference only; verify product details with suppliers before purchase.