Difference between revisions of "2-Methylpropene"

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(Imported from http://en.wikipedia.org/w/index.php?title=Isobutylene&oldid=311420873)
 
 
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|  ImageSize2 = 180px
 
|  ImageSize2 = 180px
 
| IUPACName = 2-Methylpropene
 
| IUPACName = 2-Methylpropene
|  OtherNames = Isobutene<br>gamma-Butylene<br>2-Methylpropylene
+
|  OtherNames = Isobutylene<br/>Isobutene<br/>γ-Butylene<br/>2-Methylpropylene
 
| Section1 = {{Chembox Identifiers
 
| Section1 = {{Chembox Identifiers
 +
|  InChI = 1/C4H8/c1-4(2)3/h1H2,2-3H3
 +
|  StdInChI = 1S/C4H8/c1-4(2)3/h1H2,2-3H3
 +
|  InChIKey = VQTUBCCKSQIDNK-UHFFFAOYAW
 +
|  StdInChIKey = VQTUBCCKSQIDNK-UHFFFAOYSA-N
 
|  CASNo = 115-11-7
 
|  CASNo = 115-11-7
 
|    CASNo_Ref = {{cascite}}
 
|    CASNo_Ref = {{cascite}}
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|  PubChem = 8255
 
|  PubChem = 8255
 
|  SMILES = CC(=C)C
 
|  SMILES = CC(=C)C
|  InChI = 1/C4H8/c1-4(2)3/h1H2,2-3H3
 
 
|  RTECS = UD0890000
 
|  RTECS = UD0890000
 
   }}
 
   }}
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   }}
 
   }}
 
| Section7 = {{Chembox Hazards
 
| Section7 = {{Chembox Hazards
|  Reference = <ref name="ICSC">{{ICSC-ref|1027|name=Isobutene|date=April 2000}}</ref>
+
|  Reference = <ref>{{CLP Regulation|index=601-012-00-4|page=450}}</ref><ref name="ICSC">{{ICSC-ref|1027|name=Isobutene|date=April 2000}}</ref>
 
|  EUIndex = 601-012-00-4
 
|  EUIndex = 601-012-00-4
|  EUClass = Extremely flammable ('''F+''')
 
|  RPhrases = {{R12}}
 
|  SPhrases = {{S2}}, {{S9}}, {{S16}}, {{S33}}
 
 
|  GHSPictograms = {{GHS02|Flam. Gas 1}}{{GHS04|Press. Gas}}
 
|  GHSPictograms = {{GHS02|Flam. Gas 1}}{{GHS04|Press. Gas}}
 
|  GHSSignalWord = DANGER
 
|  GHSSignalWord = DANGER
 
|  HPhrases = {{H-phrases|220}}
 
|  HPhrases = {{H-phrases|220}}
 
|  PPhrases = {{P-phrases|210|377|381|403}}
 
|  PPhrases = {{P-phrases|210|377|381|403}}
|  NFPA-H = 1
 
|  NFPA-F = 4
 
|  NFPA-R = 0
 
|  NFPA-O =
 
 
|  FlashPt = flammable gas
 
|  FlashPt = flammable gas
 
|  Autoignition = 465 °C (869 ºF)
 
|  Autoignition = 465 °C (869 ºF)
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   }}
 
   }}
 
| Section8 = {{Chembox Related
 
| Section8 = {{Chembox Related
|  OtherFunctn = [[1-Butene]]<br/>[[Cis-2-Butene|''cis''-2-Butene]]<br/>[[Trans-2-Butene|''trans''-2-Butene]]
+
|  OtherFunctn = [[But-1-ene]]<br/>[[(E)-But-2-ene|(''E'')-But-2-ene]]<br/>[[(Z)-But-2-ene|(''Z'')-But-2-ene]]
 
|    Function = [[butene]]s
 
|    Function = [[butene]]s
 
|  OtherCpds = [[Isobutane]]
 
|  OtherCpds = [[Isobutane]]
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}}
 
}}
  
'''Isobutylene''' (or 2-methylpropene) is a [[hydrocarbon]] of significant industrial importance.  It is a four-carbon branched [[alkene]] (olefin), one of the four [[isomers of butylene]].  At standard temperature and pressure it is a colorless flammable gas.
+
'''2-Methylpropene''' (or '''isobutylene''') is a [[hydrocarbon]] of significant industrial importance.  It is a four-carbon branched [[alkene]] (olefin), one of the four [[isomers of butylene]].  At standard temperature and pressure it is a colorless flammable gas.
  
 
==Uses==
 
==Uses==
Isobutylene is used as an intermediate in the production of a variety of products.  It is reacted with [[methanol]] and [[ethanol]] in the manufacture of the gasoline oxygenates [[methyl tert-butyl ether]] (MTBE) and [[ethyl tert-butyl ether]] (ETBE), respectively.  [[Alkylation]] with butane produces [[isooctane]], another fuel additive.  Isobutylene is also used in the production of [[methacrolein]].  [[Polymerization]] of isobutylene produces [[butyl rubber]] (polyisobutylene).  Antioxidants such as [[butylated hydroxytoluene]] (BHT) and [[butylated hydroxyanisole]] (BHA) are produced by [[Friedel-Crafts alkylation]] of [[phenol]]s using isobutylene.
+
2-Methylpropene is used as an intermediate in the production of a variety of products.  It is reacted with [[methanol]] and [[ethanol]] in the manufacture of the gasoline oxygenates [[methyl tert-butyl ether]] (MTBE) and [[ethyl tert-butyl ether]] (ETBE), respectively.  [[Alkylation]] with butane produces [[isooctane]], another fuel additive.  2-Methylpropene is also used in the production of [[methacrolein]].  [[Polymerization]] of isobutylene produces [[butyl rubber]] (polyisobutylene).  Antioxidants such as [[butylated hydroxytoluene]] (BHT) and [[butylated hydroxyanisole]] (BHA) are produced by [[Friedel-Crafts alkylation]] of [[phenol]]s using 2-methylpropene.
  
 
==Manufacture==
 
==Manufacture==
Isobutylene can be isolated from refinery streams by reaction with [[sulfuric acid]], but the most common industrial method for its production is by [[catalysis|catalytic]] [[dehydrogenation]] of [[isobutane]].<ref>{{citation | title = Hydrocarbon Chemistry | first1 = George A. | last1 = Olah | authorlink1 = George Andrew Olah | first2 = Árpád | last2 = Molnár | publisher = Wiley-Interscience | isbn = 978-0471417828}}.</ref>  In the 1990s, the production of isobutylene increased dramatically as the demand for oxygenates such as MTBE grew. Key manufacturers of this product are Texas Petrochemicals and Lyondell in North America.
+
2-Methylpropene can be isolated from refinery streams by reaction with [[sulfuric acid]], but the most common industrial method for its production is by [[catalysis|catalytic]] [[dehydrogenation]] of [[isobutane]].<ref>{{citation | title = Hydrocarbon Chemistry | first1 = George A. | last1 = Olah | authorlink1 = George Andrew Olah | first2 = Árpád | last2 = Molnár | publisher = Wiley-Interscience | isbn = 978-0471417828}}.</ref>  In the 1990s, the production of 2-methylpropene increased dramatically as the demand for oxygenates such as MTBE grew. Key manufacturers of this product are Texas Petrochemicals and Lyondell in North America.
  
 
==Safety==
 
==Safety==
Isobutylene is a highly flammable gas and presents an explosion danger.  Usually stored as a compressed gas, if released it may produce an oxygen-deficient atmosphere that presents an asphyxiation hazard.<ref name="ICSC"/>
+
2-Methylpropene is a highly flammable gas and presents an explosion danger.  Usually stored as a compressed gas, if released it may produce an oxygen-deficient atmosphere that presents an asphyxiation hazard.<ref name="ICSC"/>
  
 
==See also==
 
==See also==
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*{{SIDS|id=115117|name=Isobutylene|date=November 2003}}
 
*{{SIDS|id=115117|name=Isobutylene|date=November 2003}}
  
 +
{{DEFAULTSORT:Methylpropene-2}}
 
[[Category:Alkenes]]
 
[[Category:Alkenes]]
  
 
{{Imported from Wikipedia|name=Isobutylene|id=311420873}}
 
{{Imported from Wikipedia|name=Isobutylene|id=311420873}}

Latest revision as of 02:29, 2 September 2009

2-Methylpropene
Isobutylene.png
Isobutylene2.png
Isobutylene3.png
IUPAC name 2-Methylpropene
Other names Isobutylene
Isobutene
γ-Butylene
2-Methylpropylene
Identifiers
InChI InChI=1/C4H8/c1-4(2)3/h1H2,2-3H3
InChIKey VQTUBCCKSQIDNK-UHFFFAOYAW
Standard InChI InChI=1S/C4H8/c1-4(2)3/h1H2,2-3H3
Standard InChIKey VQTUBCCKSQIDNK-UHFFFAOYSA-N
CAS number [115-11-7]
EC number 204-066-3
UN number 1055
In Liquefied petroleum gas: 1075
RTECS UD0890000
ChemSpider 7957
PubChem 8255
SMILES
Properties[1]
Molecular formula C4H8
Molar mass 56.11 g mol−1
Appearance Colorless gas
Density 0.5879 g/cm3, liquid
Melting point

−140.3 ºC

Boiling point

-6.9 °C, 266 K, 20 °F

Solubility in water Insoluble
Hazards[2][3]
EU index number 601-012-00-4
GHS pictograms Flam. Gas 1Press. Gas
GHS signal word DANGER
GHS hazard statements H220
GHS precautionary statements P210, P377, P381, P403
Flash point flammable gas
Autoignition temp. 465 °C (869 ºF)
Explosive limits 1.8–9.6%
Related compounds
Other butenes But-1-ene
(E)-But-2-ene
(Z)-But-2-ene
Other compounds Isobutane
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

2-Methylpropene (or isobutylene) is a hydrocarbon of significant industrial importance. It is a four-carbon branched alkene (olefin), one of the four isomers of butylene. At standard temperature and pressure it is a colorless flammable gas.

Uses

2-Methylpropene is used as an intermediate in the production of a variety of products. It is reacted with methanol and ethanol in the manufacture of the gasoline oxygenates methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE), respectively. Alkylation with butane produces isooctane, another fuel additive. 2-Methylpropene is also used in the production of methacrolein. Polymerization of isobutylene produces butyl rubber (polyisobutylene). Antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) are produced by Friedel-Crafts alkylation of phenols using 2-methylpropene.

Manufacture

2-Methylpropene can be isolated from refinery streams by reaction with sulfuric acid, but the most common industrial method for its production is by catalytic dehydrogenation of isobutane.[4] In the 1990s, the production of 2-methylpropene increased dramatically as the demand for oxygenates such as MTBE grew. Key manufacturers of this product are Texas Petrochemicals and Lyondell in North America.

Safety

2-Methylpropene is a highly flammable gas and presents an explosion danger. Usually stored as a compressed gas, if released it may produce an oxygen-deficient atmosphere that presents an asphyxiation hazard.[3]

See also

References

  1. The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 11th ed.; Merck, 1989. ISBN 091191028X, 5024.
  2. Index no. 601-012-00-4 of Annex VI, Part 3, to Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006. OJEU L353, 31.12.2008, pp 1–1355 at p 450.
  3. 3.0 3.1 Isobutene; International Chemical Safety Card 1027; International Labour Organization: Geneva, April 2000, <http://www.inchem.org/documents/icsc/icsc/eics1027.htm>
  4. Olah, George A.; Molnár, Árpád Hydrocarbon Chemistry; Wiley-Interscience. ISBN 978-0471417828.

External links

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Wikipedia-logo.png This page was originally imported from Wikipedia, specifically this version of the article "Isobutylene". Please see the history page on Wikipedia for the original authors. This WikiChem article may have been modified since it was imported. It is licensed under the Creative Commons Attribution–Share Alike 3.0 Unported license.