Diethyl Ether
Diethyl ether is a colorless, highly volatile flammable liquid and organic compound. Diethyl ether is also called ethoxyethane, ethyl ether, sulfuric ether, or ether. It is part of the ether class, meaning it contains an ether group or an oxygen atom connected to two alkyl or aryl groups. The general formula for the ether group is R-O-R. Ethers are typical in organic and biochemistry, because they are common links in carbohydrates and lignin. Technical-grade ether and anesthetic ether are the two grades available for commercial use. Technical-grade ether standardly does not contain peroxides, though no worldwide parameters exist. Anesthetic diethyl ether must pass the tests for aldehydes and peroxides, have a natural reaction, contain no foreign odors, and have a water content of 0.2% or below.
In 1540, Valerius Cordus first produced diethyl ether through the distillation of ethanol and sulfuric acid. Diethyl ether can be produced in laboratories and on the industrial scale through the acid ether synthesis. It is mostly created as a byproduct of the vapor-phase hydration of ethylene to produce ethanol, with the use of solid-supported phosphoric acid catalysts. Ethanol is mixed with sulfuric acid or another strong acid, which splits into smaller particles, producing hydronium ions. A hydrogen ion gives the ethanol molecule a positive charge. Then a nucleophilic oxygen atom of ethanol displaces a water molecule of the positively charged ethanol molecule to make water, a hydrogen ion, and diethyl ether. This reaction must occur at temperatures below 302° F. The Williamson Ether Synthesis can also make diethyl ether through an alkoxide performing a nucleophilic substitution upon an alkyl halide. However, in countries where ethanol is made by chemical synthesis, diethyl ether is created in large enough amounts as a byproduct that synthesis is unneeded. Either way, the production methods result in diethyl ether, or (C2H5)2O. Ether has many applications, including as a solvent, reagent, or as an anesthesia. A solvent is a liquid that dissolves another substance, which is called a solute, without changing chemically. Ether is used as a solvent in the lab typically in liquid-liquid reactions and in the Grignard reaction. (To learn more about the Grignard reaction, click here or here.) Due to its high tendency to vaporize and low flash point, ether can be used as a starting fluid with petroleum distillates for gasoline and diesel engines. In the past, diethyl ether was injected in the veins as a means to assess a patient's heart status by determining his or her circulation rate. It was also injected, when in an isotonic sodium solution and dextrose solution, to settle manic patients. Diethyl ether was utilized to make expressing and releasing repressed emotions through reliving the, usually traumatic, experience easier when treating people in psychoneurotic states. Also, ether used to be mixed with alcohol, forming ether spirit, and orally given as preparation for medical care of gastric flatulence and milder forms of gastralgia. It relieved the buildup of gas in the alimentary canal. Diethyl ether was also used as a surface antiseptic, a cleaning agent, and was incorporated into cough medicines. In the US, the use of diethyl ether as a pharmaceutical was prohibited before June of 1917. Diethyl ether was also used by Polish peasants as a recreational drug in the 19th century and early 20th century and is still used by Lemkos. In addition, diethyl ether has anesthetic applications. Anesthetics are gases or volatile fluids that differ in the speed at which they cause anesthesia and in potency. Also, anesthetics vary in the level of circulation, respiratory, or neuromuscular depression they yield and in pain-relieving effects. Inhalation anesthetics have the benefit of being able to quickly change the amount of anesthesia by changing the inhaled concentration, which is not possible with intravenous agents. Due to this, inhalation anesthetics allow for respiratory depression after operations to be brief. As early as 1840, doctors in Britain knew of ether’s anesthetic properties, and it was extensively prescribed in combination with opium. As early as March 30th, 1842, Crawford Williamson Long, M.D., used ether as a general anesthetic in surgery, which he demonstrated to officials in Georgia. Following inhalation, diethyl ether is absorbed into the bloodstream and then delivered quickly to the brain. Most of diethyl ether is excreted through exhalation, though some escapes through the urine, milk, sweat, and other body fluids, and a small amount is excreted via diffusion through the intact skin. The diethyl that is not excreted is metabolized to ethanol and acetaldehyde, which are swiftly oxidized to acetate that then enters intermediate metabolism. Etherization reduces the the general level of metabolism. Diethyl ether can cause unconsciousness as a result of several processes. The interaction with membrane lipids or hydrophobic regions of specific membrane-bound proteins may cause unconsciousness. Also, it is possible that diethyl ether changes the shape of an ion channel protein, perhaps the GABA receptor, and thus alters the function of the protein, leading to a lack of consciousness. The anesthetic effects may be caused by lipid and protein membrane components connected to neuronal function. Beneficially, diethyl ether has a larger difference between an effective dose and toxic dose than chloroform, causing diethyl ether to widely replace chloroform’s use as a general anesthetic. Now ether is hardly used due to the flammable liquid’s replacement by nonflammable fluorinated hydrocarbon anesthetics. |
The ether group R-O-R
Valerius Cordus
Crawford Williamson Long, M.D.
|