2-Methyl-2-butene

HCID 10553CAS 513-35-9

Basic information

Standard SMILES
CC=C(C)C
InChIKey
BKOOMYPCSUNDGP-UHFFFAOYSA-N
Molecular formula
C5H10
Average molar mass
70.13 g/mol
Monoisotopic mass
70.07825032

Overview

2-methyl-2-butene appears as a clear colorless liquid with a petroleum-like odor. Less dense than water and insoluble in water. Hence floats on water. Vapors heavier than air.

Names & identifiers

Preferred name
2-Methyl-2-butene
IUPAC
2-methylbut-2-ene
English name
2-Methyl-2-butene
Molecular formula
C5H10
Molecular weight
70.13

Names & synonyms

2-Methyl-2-butene2-Methylbut-2-ene513-35-9AMYLENETrimethylethylene2-Butene, 2-methyl-n-Amylenebeta-Isoamylene3-Methyl-2-butene2-Methylbutene-21,1,2-TrimethylethyleneEthylene, trimethyl-
Show more names
PENTENEISOAMYLENEMethyl butene2-methyl-2-buten2-Mdethyl-2-butene
.beta.-IsoamyleneMFCD00009276NSC 74118HR68LQ4T3X(CH3)2C=CHCH3NSC-741182-Methyl-2-butene, Technical Grade 90%28265-98-7

Database identifiers

CAS
513-35-9
PubChem CID
10553
DTXSID
DTXSID8027165
ChEBI
CHEBI:28798
UNII
HR68LQ4T3X
EC Number
208-156-3
Nikkaji
J6.280D

Properties

Computed structural properties

XLogP
2.3
Topological polar surface area
0 Ų
Hydrogen bond donors
0
Hydrogen bond acceptors
0
Rotatable bonds
0
Heavy atoms
5

Experimental & physicochemical properties

Chemical Classes · 2 items

Other Classes -> Aliphatics, Unsaturated

Flammable agents - 4th degree

SpringerMaterials PropertiesBoiling point
LogP2.67
OdorDisagreeable odor
Density · 2 items

0.66 @ 15 °C/4 °C

0.6623 @ 20°C

Viscosity3.1641X10-3 Pa/s @ 139.39 K

Physicochemical properties

Melting point
-134 °C · -134 °C (lit.)
Boiling point
35 · 35-38 °C (lit.)
Density
0.662 g/mL · 0.662 g/mL at 25 °C (lit.)
vapor density
2.4 · 2.4 (vs air)
vapor pressure
25.7 psi · 25.7 psi ( 55 °C)
refractive index
20 · n20/D 1.385(lit.)

Safety & regulation

GHS classification

GHS Classification · 6 items

This chemical does not meet GHS hazard criteria for 4.1% (14 of 341) of reports.

Danger

H224 (21.4%): Extremely flammable liquid and vapor [Danger Flammable liquids]

P203, P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P273, P280, P301+P316, P301+P317, P302+P352, P303+P361+P353, P304+P340, P318, P319, P321, P330, P331, P332+P317, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 341 reports by companies from 19 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Danger

Hazard information

Regulatory Information · 5 items

Chemical: 2-Butene, 2-methyl-

2-Butene, 2-methyl- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of 2-Butene, 2-methyl- are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 31-07-2015 https://echa.europa.eu/registration-dossier/-/registered-dossier/13878

2-Butene, 2-methyl-: HSNO Approval: HSR001257 Approved with controls

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Other Safety InformationIMAP assessments - 2-Butene, 2-methyl-: Human health tier I assessment
DOT LabelFlammable Liquid
Fire Hazards · 3 items

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

· HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.

· HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.

Fire PotentialHIGHLY FLAMMABLE
Health Hazards · 3 items

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

CAUTION: Petroleum crude oil (UN1267) may contain TOXIC hydrogen sulphide gas.

CAUTION: Petroleum crude oil (UN1267) may contain TOXIC hydrogen sulphide gas.

Safety & protection

Fire FightingExcerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:
Accidental Release Measures · 4 items

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

First Aid · 3 items

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

General First Aid:

General First Aid:

Exposure Control and Personal Protection · 2 items

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear positive pressure self-contained breathing apparatus (SCBA).

Nonfire Spill ResponseExcerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:
Disposal Methods · 2 items

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

Incineration: Spray into a furnace. Incineration will become easier by mixing with a more flammable solvent.

Toxicology

TreatmentTreatment is mainly symptomatic and supportive. Gastric lavage, emesis, and the administration of activated charcoal should be avoided, as vomiting increases the risk of aspiration. (A600)
Health EffectsPetroleum distillates are aspiration hazards and may cause pulmonary damage, central nervous system depression, and cardiac effects such as cardiac arrhythmias. They may also affect the blood, immune system, liver, and kidney. (A600, L1297)
Environmental Fate · 3 items

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 68(SRC), determined from a structure estimation method(2), indicates that amylene is expected to have high mobility in soil(SRC). Volatilization of amylene from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 0.110 atm-cu m/mole(3). The potential for volatilization of amylene from dry soil surfaces may exist based upon a vapor pressure of 468 mm Hg(4).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 68(SRC), determined from a structure estimation method(2), indicates that amylene is not expected to adsorb to suspended solids and sediment in water(SRC). Based on exposure of activated sludge to amylene in the Warburg respirometer test at 20 °C, percent theoretical oxygen demand after 24 hrs was 0.9(3). Volatilization from water surfaces is expected(4) based upon a Henry's Law constant of 0.110 atm-cu m/mole(5). Volatilization half-lives for a model river and model lake are 2.5 and 80 hrs, respectively(SRC), using an estimation method(4). According to a classification scheme(6), an estimated BCF of 23(4,SRC), from a log Kow(7,SRC), suggests the potential for bioconcentration in aquatic organisms is low.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), amylene, which has a vapor pressure of 468 mm Hg at 25 °C(2), is expected to exist solely in the vapor phase in the ambient atmosphere. Vapor-phase amylene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 4.4 hrs(SRC), calculated from its rate constant of 8.69X10-11 cu cm/molecule-sec at 25 °C(3). The rate constant for the vapor-phase reaction of amylene with ozone is 4.2X10-16 cu cm/molec sec(4); the half-life for this reaction in air is estimated to be 39 minutes at an atmospheric concn of 7X10+11 molec/cu cm for ozone(5). The rate constant for the vapor-phase reaction of amylene with the nitrate radical is 9.0X10-12 cu cm/molec sec(4); the half-life for this reaction in air is estimated to be 321 seconds at an ambient concn of 2.4X10+8 molec/cu cm at night(5).

Adverse EffectsNeurotoxin - Acute solvent syndrome
Exposure RoutesOral (L400) ; inhalation (L400) ; dermal (L400)
Toxicity SummaryPetroleum distillates are central nervous system depressants and cause pulmonary damage. (A600)

Safety data

PPE
Eyeshields, Faceshields, Gloves
wgk
3
tsca
TSCA listed
ridadr
UN 2460
hs_code
29012900
risk_code
11-22-65-51/53-12-36/37/38-19-68-67-38-52/53-40-36/37

Chemistry & industry

Pharmacology

Metabolism/MetabolitesVolatile hydrocarbons are absorbed mainly through the lungs, and may also enter the body after ingestion via aspiration. (A600)

Uses & manufacturing

Uses · 6 items

Used as a chemical intermediate for isoprene and tertiary pentyl alcohol (pharmaceutical solvent); as an additive in high octane fuel manufacture; for hydrogenation, halogenation, alkylation, and condensation reactions; [HSDB] Used as an intermediate in the production of hydrocarbon resins, as a stabilizer for chloroform, and as a component of natural gas and crude oil; [eChemPortal: SIDSUNEP] Was used as an anesthetic in humans; [ACGIH]

Petroleum Production and Refining [Category: Industry]

PRINCIPALLY CHEM INT FOR ISOPRENE; ADDITIVE IN HIGH OCTANE FUEL MFR; CHEM INT FOR THE PHARMACEUTICAL SOLVENT, TERTIARY PENTYL ALCOHOL

Organic synthesis; hydrogenation, halogenation, alkylation, condensation reactions

Octane additive

Pentenes are components of gasoline and are often produced as by-products of catalytic of thermal cracking of petroleum. (L1287)

U.S. Production · 4 items

2023: 25,000,000 - <40,000,000 lb

(1972) 1.45X10+11 GRAMS (PENTENES, MIXED)

(1975) 1.27X10+11 GRAMS (AMYLENES & PENTENES)

(1984) 697,131,000 lbs /Pentenes mixed/

Consumer UsesIntermediate
Industry UsesOther
Methods of Manufacturing · 3 items

DISTILLATION OF A CATALYTICALLY CRACKED GASOLINE STREAM, FOLLOWED BY EXTRACTION WITH AQUEOUS SULFURIC ACID AT LOW TEMP

Prepd by dehydration of tert-amyl alcohol in presence of p-toluenesulfonic acid

... A component of refinery gas.

Formulations/PreparationsGrades: 90%, 95% (Technical), 99% (Pure), & Research.
Applications · 3 items

Description2-Methyl-2-butene (also named as Amylene) is an alkene hydrocarbon with the molecular formula C5H10. It is a colorless to pale yellow clear liquid. It can be used as a free radical scavenger in trichloromethane and dichloromethane. It was used for the alkylation of 3-methylthiophene over a zeolitic catalyst. It was also used as a precursor of peroxyacetyl nitrate for calibration purpose.

Uses2-Methyl-2-butene is used to prepare 3-Brom-2.3-dimethyl-1.1-dicyan-butan in the presence of 2,2'-azobis-(2,4-dimethyl-4-methoxyvaleronitrile) as a catalyst. It may be employed as precursor for peroxyacetyl nitrate for the calibration purposes.

General Description2-methyl-2-butene appears as a clear colorless liquid with a petroleum-like odor. Less dense than water and insoluble in water. Hence floats on water. Vapors heavier than air.

Preparation methods

Preparation2-methyl-2-butene is prepared by dehydration of tert-amyl alcohol in presence of p-toluenesulfonic acid or distillation of a catalytically cracked gasoline stream, followed by extraction with aqueous sulfuric acid at low temp.

Additional notes

DefinitionChEBI: 2-Methyl-2-butene is an alkene that is ethylene in which three of the hydrogens are replaced by methyl groups.

Related reactions

970 records

Linked notes

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