CompoundList
Sign in
Hydrocarbons

Dimethylacetylene

Also known as 4-butyne, but-4-yne, 2-Butyne

CAS 503-17-3Formula C4H6Molar mass 54.09 g/molEC 207-962-2
GHS signal word: Danger. Pictograms: Flammable, Harmful or irritant 5 suppliers listed
Get quotes Compare 5 suppliers
Dimethylacetylene chemical structure, C4H6, CAS 503-17-3
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
503-17-3
Formula
C4H6
Physical form
Liquid
HS code
290129
Category
Hydrocarbons
UN number
UN 1144
Illustrative photo, closed blue jerry cans in a warehouse
Typical packagingIllustrative packaging image, not the actual product

What is Dimethylacetylene?

Plain description, key identifiers and synonyms

Crotonylene appears as a clear colorless liquid with a petroleum-like odor. Less dense than water and insoluble in water. Vapors heavier than air.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
but-2-yne
CAS number
503-17-3 CAS number cross-checkedOther or deprecated CAS: 25684-85-9
EC number
207-962-2
Molecular formula
C4H6
UNII
LKE6D3018E
MDL number
MFCD00009275
InChIKey
XNMQEEKYCVKGBD-UHFFFAOYSA-N
InChI
InChI=1S/C4H6/c1-3-4-2/h1-2H3
SMILES (canonical and isomeric)
CC#CC

Synonyms

  • 4-butyne
  • but-4-yne
  • 2-Butyne
  • But-2-yne
  • Crotonylene
  • dimethyl acetylene
  • 2-Butine
  • 2-Butyne, 99%
  • CH3C.$.CCH3
  • UN 1144
  • Crotonylene [UN1144] [Flammable liquid]

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Physical form
Liquidexp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
54.09 g/molcalc.
Exact mass
54.047 Dacalc.
LogP (octanol/water)
1.03calc.
Topological polar surface area
0 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
0calc.
Rotatable bonds
0calc.
Heavy atoms
4calc.
Rings
0calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0.5calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS02: Flammable
Flammable
GHS07: Harmful or irritant
Harmful or irritant

Hazard statements

  • H224Extremely flammable liquid and vapour.
  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
  • H335May cause respiratory irritation.
Precautionary statements (25)
  • P210Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • P233Keep container tightly closed.
  • P240Ground and bond container and receiving equipment.
  • P241Use explosion-proof electrical, ventilating and lighting equipment.
  • P242Use non-sparking tools.
  • P243Take action to prevent static discharges.
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P302 + P352If on skin: Wash with plenty of water.
  • P303 + P361 + P353If on skin (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P332 + P317If skin irritation occurs: Get medical help.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P370 + P378In case of fire: Use appropriate media to extinguish.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P403 + P235Store in a well-ventilated place. Keep cool.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.
UN number
UN 1144
Transport hazard class
3
Packing group
I

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Dimethylacetylene suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 5 suppliers
5 of 5 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

5 suppliers in 2 countries

Send one request to many suppliers

Choose up to 10 suppliers or let us match your request. Compare quotes side by side, free.

Choose suppliersPost a request

Dimethylacetylene price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

Get latest price

Uses and applications

What the substance is used for, by industry and function

Applications are not documented for this substance yet. Suppliers often describe uses on their product pages, linked in the suppliers list above.

Regulatory status

Inventories, regulations and trade controls that list this substance

United States

  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Dimethylacetylene is traded under.

HS 2901.29Indicative HS code

Unsaturated, other

World exports in 2024
$2.65B
−3.2% vs 2023, imports $2.57B
2019 to 2024
Top exporters
  1. United States43.9%
  2. South Africa15.3%
  3. Qatar * partner reported9.0%
Top importers
  1. Singapore10.9%
  2. United States10.1%
  3. South Korea8.7%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Dimethylacetylene is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Dimethylacetylene, based on the data on this page

What is Dimethylacetylene?

Crotonylene appears as a clear colorless liquid with a petroleum-like odor. Less dense than water and insoluble in water. Vapors heavier than air.

What is the CAS number of Dimethylacetylene?

The CAS registry number of Dimethylacetylene is 503-17-3. Other or deprecated CAS numbers: 25684-85-9.

What is the molecular formula and weight of Dimethylacetylene?

The molecular formula of Dimethylacetylene is C4H6 and its molar mass is 54.09 g/mol.

Is Dimethylacetylene hazardous?

Dimethylacetylene carries the GHS signal word "Danger". Main hazards: extremely flammable liquid and vapour, causes skin irritation, causes serious eye irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Dimethylacetylene?

Dimethylacetylene is usually classified under HS code 290129 (Unsaturated, other). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Dimethylacetylene?

CompoundList lists 5 suppliers of Dimethylacetylene in United States and India. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Dimethylacetylene in India?

1 supplier in India list Dimethylacetylene on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of Dimethylacetylene?

Suppliers quote Dimethylacetylene on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Dimethylacetylene

Get quotes for Dimethylacetylene

Post one free request with your grade, quantity and destination. Matching suppliers send quotes you can compare side by side.
Post a request Sell Dimethylacetylene
Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
Embed this structure on your websiteShow code

Paste this code into your page to show the 2D structure of Dimethylacetylene with a 3D view, its CAS number where known and a link back to this page. Free to use with the link kept.

<iframe src="https://www.compoundlist.com/embed/structure/dimethylacetylene-503-17-3" title="Dimethylacetylene structure on CompoundList" width="360" height="420" style="border:1px solid #E7E2DA;border-radius:12px;max-width:100%" loading="lazy" referrerpolicy="strict-origin-when-cross-origin"></iframe>
Preview the embed

Explore more in Hydrocarbons or HS code 290129

5 suppliers
Free quotes, contact stays private
Get quotes