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Diethyl ether by whrget hegh
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Diethyl ether |
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Alchemist Raymundus Lullus is credited with discovering the compound in AD 1275, although there is no contemporary evidence of this. It was first synthesized in 1540 by Valerius Cordus, who called it "sweet oil of vitriol" (oleum dulce vitrioli) the name reflects the fact that it is obtained by distilling a mixture of ethanol and sulfuric acid (then known as oil of vitriol)nd noted some of its medicinal properties. At about the same time, Theophrastus Bombastus von Hohenheim, better known as Paracelsus, discovered ether's analgesic properties. The name ether was given to the substance in 1730 by August Siegmund Frobenius.
A cytochrome P450 enzyme is proposed to metabolize diethyl ether.
Diethyl ether inhibits alcohol dehydrogenase, and thus slows the metabolism of ethanol. It also inhibits metabolism of other drugs requiring oxidative metabolism.
It is particularly important as a solvent in the production of cellulose plastics such as cellulose acetate.
Diethyl ether has a high cetane number of 85 - 96 and is used as a starting fluid for diesel and gasoline engines because of its high volatility and low autoignition temperature. For the same reason it is also used as a component of the fuel mixture for carbureted compression ignition model engines.
Diethyl ether is a common laboratory solvent. It has limited solubility in water, thus it is commonly used for liquid-liquid extraction. Being less dense than water, the ether layer is usually on top. Diethyl ether is a common solvent for the Grignard reaction, and for many other reactions involving organometallic reagents. Due to its immiscibility with water and the fact that non-polar organic compounds are highly soluble in it, ether is also used in the production of freebase cocaine, and is listed as a Table II precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances.
Panel from monument in Boston commemorating Morton's demonstration of ether's anesthetic use.
William T.G. Morton participated in a public demonstration of ether anesthesia on October 16, 1846 at the Ether Dome in Boston, Massachusetts. However, Crawford Williamson Long, M.D., is now known to have demonstrated its use privately as a general anesthetic in surgery to officials in Georgia, as early as March 30, 1842, and Long publicly demonstrated ether's use as a surgical anesthetic on numerous occasions before 1846.
Ether was sometimes used in place of chloroform because it had a higher therapeutic index, a larger difference between the recommended dosage and a toxic overdose. Ether is still the preferred anesthetic in some developing nations due to its high therapeutic index (~1.5-2.2) [dubious discuss] and low price. Because of its associations with Boston, the use of ether became known as the "Yankee Dodge."
Today, ether is rarely used. The use of flammable ether was displaced by nonflammable anesthetics such as halothane. Additionally, ether had many undesirable side effects, such as postanesthetic nausea and vomiting. Modern anesthetic agents, such as methyl propyl ether (Neothyl) and methoxyflurane (Penthrane) reduce these side effects.
The anesthetic effects of ether have made it a recreational drug, although not a popular one. Diethyl ether is not as toxic as other solvents used as recreational drugs.
Ether, mixed with ethanol, was marketed in the 19th century as a cure-all and recreational drug[citation needed], during one of Western society's temperance movements. At the time, it was considered improper for women to consume alcoholic beverages at social functions, and sometimes ether-containing drugs would be consumed instead.[citation needed] A cough medicine called Hoffmann's Drops was marketed at the time as one of these drugs, and contained both ether and alcohol in its capsules. Ether tends to be difficult to consume alone, and thus was often mixed with drugs like ethanol for recreational use. Ether may also be used as an inhalant.
Ether is a traditional and still relatively popular recreational drug among Lemkos. It is usually consumed in a small quantity (kropka, or ot) poured over milk, water with sugar or orange juice in a shot glass.
Most diethyl ether is produced as a byproduct of the vapor-phase hydration of ethylene to make ethanol. This process uses solid-supported phosphoric acid catalysts and can be adjusted to make more ether if the need arises. Vapor-phase dehydration of ethanol over some alumina catalysts can give diethyl ether yields of up to 95% .
Diethyl ether can be prepared both in laboratories and on an industrial scale by the acid ether synthesis. Ethanol is mixed with a strong acid, typically sulfuric acid, H2SO4. The acid dissociates producing hydrogen ions, H+. A hydrogen ion protonates the electronegative oxygen atom of the ethanol, giving the ethanol molecule a positive charge:
CH3CH2OH + H+ CH3CH2OH2+
A nucleophilic oxygen atom of unprotonated ethanol displaces a water molecule from the protonated (electrophilic) ethanol molecule, producing water, a hydrogen ion and diethyl ether.
CH3CH2OH2+ + CH3CH2OH H2O + H+ + CH3CH2OCH2CH3
This reaction must be carried out at temperatures lower than 150 C in order to ensure that an elimination product (ethylene) is not product of the reaction. At higher temperatures, ethanol will dehydrate to form ethylene. The reaction to make diethyl ether is reversible, so eventually an equilibrium between reactants and products is achieved. Getting a good yield of ether requires that ether be distilled out of the reaction mixture before it reverts to ethanol, taking advantage of Le Chatelier's principle.
Another reaction that can be used for the preparation of ethers is the Williamson ether synthesis, in which an alkoxide (produced by dissolving an alkali metal in the alcohol to be used) performs a nucleophilic substitution upon an alkyl halide.
Diethyl ether is prone to peroxide formation, and can form explosive diethyl ether peroxide. Ether peroxides are higher boiling and are contact explosives when dry. Diethyl ether is typically supplied with trace amounts of the antioxidant BHT (2,6-di-tert-butyl-4-methylphenol), which reduces the formation of peroxides. Storage over NaOH precipitates the intermediate ether hydroperoxides. Water and peroxides can be removed by either distillation from sodium and benzophenone, or by passing through a column of activated alumina.
Ether is extremely flammable. The autoignition temperature of ether is only 170 C (338F), so it can be ignited by a hot surface without a flame or spark. A common practice in chemical labs is to use steam (thus limiting the temperature to 100 C (212 F) when ether must be heated or distilled. The diffusion of diethyl ether in air is 0.918105 m2/s (298K 101.325 kPa).
Recreational use of diethyl ether was portrayed in the novel Fear and Loathing in Las Vegas by Hunter S. Thompson, who compared its effects to the behavior of a "village drunkard in some early Irish novel". It was also portrayed in the novel The Cider House Rules by John Irving and in the film adaptation of the same name. Another important example of this practice appears in the novel Belle du Seigneur by Albert Cohen, where the protagonists use it as a last resort to boredom in their relationship. An example of ether being used as a drug in the 19th century is to be found in Italo Svevo's novel Senilit (1898). One of the main characters, Amalia, a reticent spinster in her early thirties, becomes addicted to ether, falls into delirium and dies. William James also reports on the effects of ether in The Principles of Psychology, and is reported to have consumed it along with his students.
109. Aspergillus flavus mutant strain 241, blocked in aflatoxin biosynthesis, does not accumulate aflR transcript. Matthew P. Brown and Gary A. Payne, North Carolina State University, Raleigh, NC 27695 fgsc.net
P. T. Normann, A. Ripel and J. Morland (1987). "Diethyl Ether Inhibits Ethanol Metabolism in Vivo by Interaction with Alcohol Dehydrogenase". Alcoholism: Clinical and Experimental Research 11 (2): 163166. doi:10.1111/j.1530-0277.1987.tb01282.x.
Larry K. Keefer, William A. Garland, Neil F. Oldfield, James E. Swagzdis, and Bruce A. Mico (1985). "Inhibition of N-Nitrosodimethylamine Metabolism in Rats by Ether Anesthesia". Cancer Research 45: 545760. ;
a b "Ethers, by Lawrence Karas and W. J. Piel". Kirkthmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc. 2004.
Microsoft Word - RedListE2007.doc
a b Hill, John W. and Kolb, Doris K. Chemistry for changing times: 10th edition. Page 257. Pearson: Prentice Hall. Upper saddle river, New Jersey. 2004; Wikipedia article, Crawford W. Long.
Calderone, F.A. J. Pharmacology Experimental Therapeutics, 1935, 55(1), 24-39, Jpet.aspetjournals.org
Erowid Ether Vaults: Hoffmann's Drops
Ethyl Ether, Chem. Economics Handbook. Menlo Park, Calif: SRI International. 1991.
W. L. F. Armarego and C. L. L. Chai (2003). Purification of laboratory chemicals. Butterworth-Heinemann. ISBN 978-0750675710.
The unusual history of ether as an anesthetic, anesthesia-nursing.com
Calculation of vapor pressure, liquid density, dynamic liquid viscosity, surface tension of diethyl ether, ddbonline.ddbst.de
Anesthetic: General anesthetics (N01A)
Diethyl ether Methoxypropane Vinyl ether halogenated ethers (Desflurane Enflurane Isoflurane Methoxyflurane Sevoflurane)
Cyclopropane Ethylene Nitrous oxide# Xenon
Hexobarbital Methohexital Narcobarbital Thiopental#
Alfentanil Anileridine Fentanyl Phenoperidine Remifentanil Sufentanil
Droperidol Etomidate Fospropofol gamma-Hydroxybutyric acid Ketamine# /Esketamine Midazolam Propanidid Propofol
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