Chemistry:Nitroethane

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Nitroethane
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Names
Preferred IUPAC name
Nitroethane
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
KEGG
RTECS number
  • KI5600000
UNII
UN number UN 2842
Properties
C2H5NO2
Molar mass 75.067 g·mol−1
Appearance Colorless liquid
Density 1.054 g/cm3
Melting point −51 °C (−60 °F; 222 K)
Boiling point 114 °C (237 °F; 387 K)
Slightly soluble (4.6 g/100 ml at 20 °C)
Vapor pressure 21 mmHg (25 °C)[1]
Acidity (pKa) 16.7[2][3]
-35.4·10−6 cm3/mol
Viscosity 0.677 mPa·s at 20 °C
Hazards
Main hazards Flammable, harmful
Safety data sheet MSDS at fishersci.com
GHS pictograms GHS02: Flammable GHS06: Toxic GHS08: Health hazard
GHS Signal word DANGER
H226, H302, H315, H331, H341, H412
P210, P261, P301, P330, P304, P340, P312, P370, P378, P403+233
NFPA 704 (fire diamond)
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 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazards (white): no codeNFPA 704 four-colored diamond
3
2
3
Flash point 28 °C (82 °F; 301 K)
Explosive limits 3.4%-?[1]
Lethal dose or concentration (LD, LC):
5000 ppm (rabbit, 2 hr)[4]
6250 ppm (mouse, 2 hr)[4]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 100 ppm (310 mg/m3)[1]
REL (Recommended)
TWA 100 ppm (310 mg/m3)[1]
IDLH (Immediate danger)
1000 ppm[1]
Related compounds
Related nitro compounds
2-Nitropropane
Nitromethane
Related compounds
Ethyl nitrite
Ethyl nitrate
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
Tracking categories (test):

Nitroethane is an organic compound having the chemical formula C2H5NO2. Similar in many regards to nitromethane, nitroethane is an oily liquid at standard temperature and pressure. Pure nitroethane is colorless and has a fruity odor.

Preparation

Nitroethane is produced industrially by treating propane with nitric acid at 350–450 °C. This exothermic reaction produces four industrially significant nitroalkanes: nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane. The reaction involves free radicals, such as CH3CH2CH2O., which arise via homolysis of the corresponding nitrite ester. These alkoxy radicals are susceptible to C—C fragmentation reactions, which explains the formation of a mixture of products.[5]

Alternatively, nitroethane can be produced by the Victor Meyer reaction of haloethanes such as chloroethane, bromoethane, or iodoethane with silver nitrite in diethyl ether or THF. The Kornblum modification of this reaction uses sodium nitrite in either a dimethyl sulfoxide or dimethylformamide solvent.[6]

Uses

Via condensations like the Henry reaction, nitroethane converts to several compounds of commercial interest. Condensation with 3,4-dimethoxybenzaldehyde affords the precursor to the antihypertensive drug methyldopa; condensation with unsubstituted benzaldehyde yields phenyl-2-nitropropene, a precursor for amphetamine drugs. Nitroethane condenses with two equivalents of formaldehyde to give, after hydrogenation, 2-amino-2-methyl-1,3-propanediol, which in turn condenses with oleic acid to give an oxazoline, which protonates to give a cationic surfactant.[5]

Like some other nitrated organic compounds, nitroethane is also used as a fuel additive and a precursor to Rocket propellants.

Nitroethane is a useful solvent for polymers such as polystyrene and is particularly useful for dissolving cyanoacrylate adhesives. In cosmetics applications, it has been used as a component in artificial nail remover and in overhead ceiling sealant sprays.

Nitroethane was previously used successfully as a chemical feedstock (precursor ingredient) in laboratories for the synthesis of multitudes of substances and consumer goods. For example, the medicine Pervitin (methamphetamine) was commonly used in the 19th and 20th century, and was especially popular during WWII by troops of both sides for mood elevation, appetite and sleep suppression and increasing focus and alertness). Nitroalkanes were one of many ingredients used in the synthesis of many phenethylamines, including medications such as Pervitin and the racemic compound Benzedrine[7] (amphetamine), used as an anorectic medicine for obesity.[8]

Toxicity

Nitroethane is suspected to cause genetic damage and be harmful to the nervous system. Typical TLV/TWA is 100 ppm. Typical STEL is 150 ppm. Skin contact causes dermatitis in humans. In animal studies, nitroethane exposure was observed to cause lacrimation, dyspnea, pulmonary rales, edema, liver and kidney injury, and narcosis.[9] Children have been poisoned by accidental ingestion of artificial nail remover.[10]

The -1">50 for rats is reported as 1100 mg/kg.[11]

References

  1. 1.0 1.1 1.2 1.3 1.4 NIOSH Pocket Guide to Chemical Hazards. "#0453". National Institute for Occupational Safety and Health (NIOSH). https://www.cdc.gov/niosh/npg/npgd0453.html. 
  2. Reich, Hans. "Bordwell pKa table: "Nitroalkanes"". http://www.chem.wisc.edu/areas/reich/pkatable/. Retrieved 17 January 2016. 
  3. Matthews, Walter (1975). "Equilibrium acidities of carbon acids. VI. Establishment of an absolute scale of acidities in dimethyl sulfoxide solution". Journal of the American Chemical Society 97 (24): 7006. doi:10.1021/ja00857a010. 
  4. 4.0 4.1 "Nitroethane". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH). https://www.cdc.gov/niosh/idlh/79243.html. 
  5. 5.0 5.1 Sheldon B. Markofsky “Nitro Compounds, Aliphatic” in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. doi:10.1002/14356007.a17_401.
  6. Agrawal, Jai (2007). Organic Chemistry of Explosives. Chichester, England: John Wiley & Sons. pp. 7–10. ISBN 9780470029671. https://www.scribd.com/doc/77304293/12/Modi%EF%AC%81ed-Victor-Meyer-Reaction. 
  7. "2016 National Drug Assessment Summary". Drug Administration. November 2016. https://www.da.gov/resource-center/2016%20NDTA%20Summary.pdf. 
  8. "2016 National Drug Assessment Summary". Drug Administration. November 2016. https://www.da.gov/resource-center/2016%20NDTA%20Summary.pdf. 
  9. "Chemical Sampling Information Nitroethane." Retrieved February 9, 2007, from the website of the US Occupational Safety & Health Administration.
  10. Hornfeldt CS, Rabe WH (1994). "Nitroethane poisoning from an artificial fingernail remover". J. Toxicol. Clin. Toxicol. 32 (3): 321–4. doi:10.3109/15563659409017967. PMID 8007041. 
  11. MSDS for nitroethane (revised October 3, 2005), as reported by Fisher Scientific.

External links