Cumene

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Cumene
Skeletal formula of cumene
Ball-and-stick model of the cumene molecule
Names
Preferred IUPAC name
(1-methylethyl)benzene
Other names
Isopropylbenzene
Cumene (no longer recommended[1])
Cumol
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.002.458
KEGG
RTECS number GR8575000
UNII
Properties
C9H12
Molar mass 120.20 g·mol−1
Appearance colorless liquid
Odor sharp, gasoline-like
Density 0.862 g cm−3, liquid
Melting point −96 °C (−141 °F; 177 K)
Boiling point 152 °C (306 °F; 425 K)
negligible
Solubility soluble in acetone, ether, ethanol
Vapor pressure 8 mm (20°C)[2]
-89.53·10−6 cm3/mol
1.4915 (20 °C)
Viscosity 0.777 cP (21 °C)
Hazards
Main hazards flammable
R-phrases (outdated) R10,R37,R51/53,R65
S-phrases (outdated) S24,S37,S61,S62
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasolineHealth code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroformReactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calciumSpecial hazards (white): no codeNFPA 704 four-colored diamond
3
2
1
Flash point 43 °C (109 °F; 316 K)
424 °C (795 °F; 697 K)
Explosive limits 0.9-6.5%
Lethal dose or concentration (LD, LC):
12750 mg/kg (oral, mouse)
1400 mg/kg (oral, rat)[3]
200 ppm (mouse, 7 hr)[3]
8000 ppm (rat, 4 hr)[3]
US health exposure limits (NIOSH):
PEL (Permissible)
TWA 50 ppm (245 mg/m3) [skin][2]
REL (Recommended)
TWA 50 ppm (245 mg/m3) [skin][2]
IDLH (Immediate danger)
900 ppm[2]
Related compounds
Related compounds
ethylbenzene
toluene
benzene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Cumene is the common name for isopropylbenzene, an organic compound that is based on an aromatic hydrocarbon with an aliphatic substitution. It is a constituent of crude oil and refined fuels. It is a flammable colorless liquid that has a boiling point of 152 °C. Nearly all the cumene that is produced as a pure compound on an industrial scale is converted to cumene hydroperoxide, which is an intermediate in the synthesis of other industrially important chemicals, primarily phenol and acetone.

Production[edit]

Cumene-formation-2D-skeletal V2.svg

Commercial production of cumene is by Friedel–Crafts alkylation of benzene with propylene. Cumene producers account for approximately 20% of the global demand for benzene.[4] Previously, solid phosphoric acid (SPA) supported on alumina was used as the catalyst. Since the mid-1990s, commercial production has switched to zeolite-based catalysts.[5] The addition of two equivalents of propylene gives diisopropylbenzene (DIPB). Using transalkylation, DIPB is comproportionated with benzene.[6]

Safety[edit]

Isopropylbenzene forms peroxides upon contact with air. Tests for peroxides are routinely conducted before heating or distilling.

See also[edit]

References[edit]

  1. ^ Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. pp. 139, 597. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4. 
  2. ^ a b c d "NIOSH Pocket Guide to Chemical Hazards #0159". National Institute for Occupational Safety and Health (NIOSH). 
  3. ^ a b c "Cumene". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH). 
  4. ^ Market Study Benzene, published by Ceresana, July 2011 [1]
  5. ^ The Innovation Group website, page accessed 15/11/07
  6. ^ Bipin V. Vora, Joseph A. Kocal, Paul T. Barger, Robert J. Schmidt, James A. Johnson (2003). "Alkylation". Kirk‐Othmer Encyclopedia of Chemical Technology. doi:10.1002/0471238961.0112112508011313.a01.pub2. 

External links[edit]