Urethane

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Structural formula
Structure of urethane
General
Surname Urethane
other names
  • Ethyl carbamate
  • Ethyl urethane
  • Ethyl amidocarbonate
Molecular formula C 3 H 7 NO 2
Brief description

colorless and odorless crystals

External identifiers / databases
CAS number 51-79-6
EC number 200-123-1
ECHA InfoCard 100,000,113
PubChem 5641
ChemSpider 5439
DrugBank DB04827
Wikidata Q422884
properties
Molar mass 89.09 g · mol -1
Physical state

firmly

density

0.98 g cm −3 (21 ° C)

Melting point

49 ° C

boiling point

185 ° C

solubility
Refractive index

1.4144 (51 ° C)

safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary
08 - Dangerous to health 07 - Warning

danger

H and P phrases H: 302-350
P: 201-308 + 313
Thermodynamic properties
ΔH f 0

−517.1 kJ / mol

As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Urethane (C 3 H 7 NO 2 ) belongs to the chemical group of carbamates .

General

Urethane is not, as the name suggests, the monomer of polyurethane . Rather, urethane has the same functional group as polyurethane, namely the urethane group (-NH-CO-O-), which is present in large numbers in polyurethane. Urethane is formed formally in the reaction of isocyanic acid (HN = C = O) with z. B. ethanol or other alcohols. The urethane compound class also denotes a class of substances that contains the above-mentioned functional group, not just the urethane that bears an ethyl group (ethyl carbamate). In the case of polyurethane, the reaction between di-, tri or polyisocyanates and polyhydric alcohols takes place analogously .

Extraction and presentation

Urethane can be produced by the action of ammonia on diethyl carbonate or by heating urea nitrate together with ethanol . In addition, it can also be produced by heating (100 ° C) equimolar amounts of urea and ethanol in the presence of catalytically active concentrated sulfuric acid .

Occurrence

Urethane is a natural component of some foods, such as bread , wine, and fermented beverages. If improperly manufactured, urethane can occur in higher concentrations, especially in stone fruit brandies ( kirsch , plum brandy , mirabelle brandy ). It is known as a carcinogenic (cancer causing) compound. In Switzerland there has been an upper limit of 1 mg / l in spirits since 2003 .

use

Before 1970 it was used as a medicine to treat leukemia and varices . It is used as a long-acting injection anesthetic in animal research .

safety instructions

Urethane damages the blood-building organs, liver and the central nervous system and can cause cancer.

Individual evidence

  1. a b c d e f g Entry on ethyl carbamate in the GESTIS substance database of the IFA , accessed on July 23, 2016(JavaScript required) .
  2. Entry on urethane. In: Römpp Online . Georg Thieme Verlag, accessed on March 10, 2014.
  3. David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-240.
  4. Entry on urethanes in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
  5. David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-24.

Web links

Wiktionary: Urethane  - explanations of meanings, word origins, synonyms, translations