Diethyl ether

Description

Diethyl ether is a component of starting fluids and is used as a solvent in the manufacture of synthetic dyes and plastics. Because of its characteristics, diethyl ether was widely used in many countries as an anesthetic agent, but was then replaced by other substances in the 1960s.

Chemical properties

Ether, (C2H5)2,also known as ethyl ether, is a colorless liquid. It is used as a solvent,a denaturant, and as an anesthetic in medicine. lt is an organic compound in which two hydrocarbon radicals are joined by an atom of oxygen.

Chemical properties

Diethyl ether has very diffusive, sweet-ethereal odor. Actually a poor odorant, it gives impression of power by its very high vapor pressure at room temperature.

Physical properties

Colorless, hygroscopic, volatile liquid with a sweet, pungent odor. Odor threshold concentration is 330 ppb (quoted, Keith and Walters, 1992).

History

Ether was supposedly discovered by Raymundus Lullus (1232–1315) around 1275, although there is no extant evidence of this in his writings. The discoverer of ether is often credited to the German physician and botanist Valerius Cordus (1515–1554), who gave the first description of the preparation of ether in the mid-16th century. Cordus called the substance oleum vitrioli dulce, which is translated as sweet oil of vitriol. Cordus used sulfuric acid (oil of vitriol) to catalyze the conversion of alcohol to ether. At approximately the same time Paracelsus (1493–1541), a Swiss physician who is also cited as a discoverer of ether, observed that chickens were safely put to sleep by breathing vapors from sweet oil of vitriol. In 1730, August Siegmund Frobenius changed the name of sweet vitriol to ether.

The Uses of Diethyl ether

Diethyl ether has been used extensively as a general anesthetic.

The Uses of Diethyl ether

LiAlH4 (283 mg, 7.45 mmol) was added to a stirred solution of the SM (1.0 g, 2.98 mmol) in ether (30 mL) at 0 C. The reaction mixture was stirred at 0 C for 1 h. To the mixture was then added H20 (0.280 mL), 3N NaOH (0.280 mL), and H2O (0.840 mL). The resulting precipitate was removed by filtration and the filtrate was concentrated in vacuo to give a yellow oil. The oil (0.9 g) was purified by Prep LC [50 g silica, 0-20% (10% NH3 in MeOH)/(DCM)] to provide to product as a colorless oil. [250 mg]

The Uses of Diethyl ether

Solvent for waxes, fats, oils, perfumes, alkaloids, gums. Excellent solvent for nitrocellulose when mixed with alcohol. Important reagent in organic syntheses, especially in Grignard and Wurtz type reactions. Easily removable extractant of active principles (hormones, etc.) from plant and animal tissues. In the manufacture of gun powder. As primer for gasoline engines.

The Uses of Diethyl ether

Ethyl ether is a solvent that may cause skin irritation. Although considered a non-comedogenic raw material, it is rarely used in cosmetics.
However, being a useful extraction solvent for natural perfume and flavor materials, diethyl ether is often found in traces in the commercial, evaporated extracts. It is easier to remove ether from natural extracts, than it is to remove Hexane and other, more common solvents for perfume raw materials.

The Uses of Diethyl ether

Ethyl ether is used as a solvent for fats, oils,waxes, gums, perfumes, and nitrocellulose;in making gun powder; as an anesthetic; andin organic synthesis.

The Uses of Diethyl ether

Ether was applied topically, inhaled, and consumed for medical purposes well before it was used as an anesthetic. Ether is only slightly soluble in water (6.9%), but it is a good solvent for nonpolar organic compounds. Approximately 65% of ether production is used as a solvent for waxes, fats, oils, gums, resins, nitrocellulose, natural rubber, and other organics. As a solvent, it is used as an extracting agent for plant and animal compounds in the production of pharmaceuticals and cosmetics. Another 25% of total ether production is used in chemical synthesis. It is an intermediate used in the production of monoethanolamine (MEA, C₂H₇NO). Ether is used in the production of Grignard reagents. A Grignard reagent has the general form RMgX, where R is an alkyl or aryl group and X is a halogen. Grignard reagents are widely used in industrial organic synthesis. A Grignard reagent is typically made by reacting a haloalkane with magnesium in an ether solution, for example, CH₃I + MgCH₃MgI. Ether is a common starting fluid, especially for diesel engines.

Definition

ChEBI: An ether in which the oxygen atom is linked to two ethyl groups.

Definition

diethyl ether: A colourless flammablevolatile ether, C2H5OC2H5; r.d. 0.71;m.p. –116°C; b.p. 34.5°C. It can bemade by Williamson’s synthesis. Itis an anaesthetic and useful organicsolvent.

Production Methods

Ether is produced by the dehydration of ethanol using sulfuric acid: 2CH₃CH₂OH +2H₂SO₄ → (CH₃CH₂)₂O + H₂SO₄ + H₂O.the temperature of the reaction is carriedout at about 140°C to control for unwanted products.the volatile ether is distilled from themixture. Ether can also be prepared by Williamson synthesis. In this reaction, ethanol reactswith sodium to form sodium ethanolate (Na+C₂H₅O?). Sodium ethanolate then reacts withchloroethane to form ether and sodium chloride: Na+C₂H₅O? +C₂H₅Cl → C₂H₅OC₂H₅ +NaCl. Ether is also produced as a by-product in the production of ethanol.

General Description

A clear colorless liquid with an anesthetic odor. Flash point -49°F. Less dense than water and slightly soluble in water. Hence floats on water. Vapors are heavier than air. Used as a solvent and to make other chemicals.

Air & Water Reactions

Highly flammable. Oxidizes readily in air to form unstable peroxides that may explode spontaneously [Bretherick, 1979 p.151-154, 164]. A mixture of liquid air and Diethyl ether exploded spontaneously, [MCA Case History 616(1960)].

Reactivity Profile

Occasional explosions have occurred when aluminum hydride was stored in ether. The explosions have been blamed on the presence of carbon dioxide impurity in the ether, [J. Amer. Chem. Soc. 70:877(1948)]. Diethyl ether and chromium trioxide react violently at room temperature. Solid acetyl peroxide in contact with ether or any volatile solvent may explode violently. A 5-gram portion in ether detonated while being carried, [Chem. Eng. News 27:175(1949)]. Nitrosyl perchlorate ignites and explodes with Diethyl ether. A mixture of ether and ozone forms aldehyde and acetic acid and a heavy liquid, ethyl peroxide, an explosive, [Mellor 1:911(1946-1947)].

Hazard

CNS depressant by inhalation and skin absorption. Very flammable, severe fire and explosion hazard when exposed to heat or flame. Forms explosive peroxides. Explosive limits in air 1.85– 48%.

Health Hazard

Vapor inhalation may cause headache, nausea, vomiting, and loss of consciousness. Contact with eyes will be irritating. Skin contact from clothing wet with the chemical may cause burns.

Health Hazard

The acute toxicity of diethyl ether is low. Inhalation of high concentrations can cause sedation, unconsciousness, and respiratory paralysis. These effects are usually reversible upon cessation of exposure. Diethyl ether is mildly irritating to the eyes and skin, but does not generally cause irreversible damage. Repeated contact can cause dryness and cracking of the skin due to removal of skin oils. The liquid is not readily absorbed through the skin, in part because of its high volatility. Diethyl ether is slightly toxic by ingestion. Diethyl ether is regarded as having adequate warning properties. There is no evidence for carcinogenicity of diethyl ether, and no reproductive effects have been reported. Chronic exposure to diethyl ether vapor may lead to loss of appetite, exhaustion, drowsiness, dizziness, and other central nervous system effects.

Health Hazard

Ethyl ether is a narcotic substance and a mildirritant to the skin, eyes, and nose; at lowconcentrations, <200 ppm in air, exposure tothis compound does not produce noticeableeffects in humans. Eye and nasal irritationmay become intolerable at 250–300 ppm.Repeated exposure can cause drying andcracking of skin, due to extraction of oils.
Inhalation of its vapors at high concentra tions, above 1% (by volume in air), couldbe hazardous to human health. A concen tration of 3.5–6.5% could produce an anes thetic effect; respiratory arrest may occurabove this concentration (Hake and Rowe1963). Inhalation of 10% ethyl ether by vol ume in air can cause death (ACGIH 1986).Repeated exposure to this compound exhib ited the symptoms of exhaustion, loss ofappetite, sleepiness, and dizziness
Acute oral toxicity of ethyl ether wasfound to be low to moderate, varying withspecies. Ingestion of 300–350 mL can befatal to humans.
LC50 value, inhalation (mice): 6500 ppm/100 min
LD50 value, oral (rats): 1215 mg/kg
In a comparison with other anestheticagents, diethyl ether was reported to beless toxic than methoxyfluorane [76-38-0], halothane , and isoflurane on test animals upon repeatedexposures at subanesthetic concentrations(Chenoweth et al. 1972; Stevens et al. 1975).At 2000 ppm it did not cause hepatotoxicresponses. Matt et al. (1983) reportedthat ether exposure for 6 minutes inducedsignificant and variable elevations of serumprolactin in female goldenhamsters
In contrast to volatile hydrocarbons, therespiratory arrest caused by ethyl etherwas reversible (Swann et al. 1974). Suchreversibility, however, was observed at alower concentration, about 105 ppm for a 5-minute exposure period in mice. There is noreport of its carcinogenicity in animals orhumans.

Fire Hazard

Behavior in Fire: Vapor is heavier than air and may travel considerable distance to a source of ignition and flash back. Decomposes violently when heated.

Fire Hazard

Diethyl ether is extremely flammable (NFPA rating = 4) and is one of the most dangerous fire hazards commonly encountered in the laboratory, owing to its volatility and extremely low ignition temperature. Ether vapor may be ignited by hot surfaces such as hot plates and static electricity discharges, and since the vapor is heavier than air, it may travel a considerable distance to an ignition source and flash back. Ether vapor forms explosive mixtures with air at concentrations of 1.9 to 36% (by volume). Carbon dioxide or dry chemical extinguishers should be used for ether fires. Diethyl ether forms unstable peroxides on exposure to air in a reaction that is promoted by light; the presence of these peroxides may lead to explosive residues upon distillation.

Flammability and Explosibility

Diethyl ether is extremely flammable (NFPA rating = 4) and is one of the most dangerous fire hazards commonly encountered in the laboratory, owing to its volatility and extremely low ignition temperature. Ether vapor may be ignited by hot surfaces such as hot plates and static electricity discharges, and since the vapor is heavier than air, it may travel a considerable distance to an ignition source and flash back. Ether vapor forms explosive mixtures with air at concentrations of 1.9 to 36% (by volume). Carbon dioxide or dry chemical extinguishers should be used for ether fires. Diethyl ether forms unstable peroxides on exposure to air in a reaction that is promoted by light; the presence of these peroxides may lead to explosive residues upon distillation.

Chemical Reactivity

Reactivity with Water No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.

Industrial uses

Diethyl ether as a commercial product is available in several grades and is used as an extraction solvent, reaction solvent, and as a general anesthetic. Ethyl ether is an excellent solvent for alkaloids, dyes, fats, gums, oils, resins, and waxes. Blends of ethyl ether and ethanol are excellent solvents for cellulose nitrate used in the manufacture of guncotton, in collodion solutions and pyroxylin plastics. Ethyl ether is used in the recovery of acetic acid from aqueous solutions in the cellulose acetate and plastic industry. It is used as a starter fuel for diesel engines and as a denaturant in denatured ethanol formulations. Grignard and Wurtz-Fillig synthesis reactions use diethyl ether as an anhydrous, inert reaction medium.

Safety Profile

Moderately toxic to humans by ingestion. Poison experimentally by subcutaneous route. Moderately toxic by intraperitoneal and intravenous routes. badly toxic by inhalation. Human systemic effects by inhalation: olfactory changes. Mutation data reported. A severe eye and moderate skin irritant. Ethyl ether is not corrosive or dangerously reactive. It must not be considered safe for indlviduals to inhale or ingest. It is a depressant of the central nervous system and is capable of producing intoxication, drowsiness, stupor, and unconsciousness. Death due to respiratory failure may result from severe and continued exposure. A very dangerous fire and explosion hazard when exposed to heat or flame. A storage hazard. It auto-oxidizes to form explosive polymeric 1 -oxy-peroxides. Explosive reaction with boron triazide, bromine trifluoride, bromine pentafluoride, perchloric acid, uranyl nitrate + light, wood pulp extracts + heat. Violent reaction or igmtion on contact with halogens (e.g., bromine, chlorine), interhalogens (e.g., iodine heptafluoride), oxidants (e.g., silver perchlorate, nitrosyl perchlorate, nitryl perchlorate, chromyl chloride, fluorine nitrate, permanganic acid, nitric acid, hydrogen peroxide, peroxodisulfuric acid, iodine(VⅡ) oxide, solum peroxide, ozone, and liquid air), sulfur and sulfur compounds (e.g., sulfur when dried with peroxidzed ether, sulfuryl chloride). Can react vigorously with acetyl peroxide, air, bromoazide, ClF3, CrO3, Cr(OCl)2, LiAlH2, NOClO4,02, NClO2, (H2so4 + permanganates), K2O2, [(C2H5)3di + air], [(CH3)d + air]. To fight fire, use alcohol foam, CO2, dry chemical. Used in production of drugs of abuse. When heated to decomposition it emits acrid smoke and irritating fumes. See also ETHERS.

Potential Exposure

Ethyl ether is used as a solvent for waxes, fats, oils, perfumes, alkaloids, dyes, gums, resins, nitrocellulose, hydrocarbons, raw rubber, and smokeless powder. It is also used as an inhalation anesthetic; a refrigerant; in diesel fuels; in dry cleaning; as an extractant; and as a chemical reagent for various organic reactions

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of saltwater and inducevomiting. Do not make an unconscious person vomit.

Environmental Fate

Photolytic. The rate constant for the reaction of ethyl ether and OH radicals in the atmosphere at 300 K is 5.4 x 10^-12 cm³/molecule?sec (Hendry and Kenley, 1979).
Chemical/Physical. The atmospheric oxidation of ethyl ether by OH radicals in the presence of nitric oxide yielded ethyl formate as the major product. Minor products included formaldehyde and nitrogen dioxide. In the absence of nitric oxide, the products were ethyl formate and acetaldehyde (Wallington and Japar, 1991).
Ethyl ether will not hydrolyze (Kollig, 1993).

storage

ether should be used only in areas free of ignition sources (including hot plates, incandescent light bulbs, and steam baths), and this substance should be stored in tightly sealed metal containers in areas separate from oxidizers. Because of the tendency of diethyl ether to form peroxides on contact with air, containers should be dated upon receipt and at the time they are opened. Diethyl ether is generally supplied with additives that inhibit peroxide formation; distillation removes these inhibitors and renders the liquid more prone to peroxide formation. Material found to contain peroxides should be treated to destroy the peroxides before use or disposed of properly.

Shipping

UN1155 Diethyl ether or Ethyl ether, Hazard Class: 3; Labels: 3-Flammable liquid

Purification Methods

Usual impurities are water, EtOH, diethyl peroxide (which is explosive when concentrated), and aldehydes. Peroxides [detected by liberation of iodine from weakly acid (HCl) solutions of KI, or by the blue colour in the ether layer when 1mg of Na2Cr2O7 and 1 drop of dilute H2SO4 in 1mL of water is shaken with 10mL of ether] can be removed in several different ways. The simplest method is to pass dry ether through a column of activated alumina (80g Al2O3/700mL of ether). More commonly, 1L of ether is shaken repeatedly with 5-10mL of a solution comprising 6.0g of ferrous sulfate and 6mL of conc H2SO4 in 110mL of water. Aqueous 10% Na2SO3 or stannous chloride can also be used. The ether is then washed with water, dried for 24hours with CaCl2, filtered and dried further by adding sodium wire until it remains bright. The ether is stored in a dark cool place, until distilled from sodium before use. Peroxides can also be removed by wetting the ether with a little water, then adding excess LiAlH4 or CaH2 and leaving to stand for several hours. (This also dried the ether.) Werner [Analyst 58 335 1933] removed peroxides and aldehydes by adding 8g AgNO3 in 60mL of water to 1L of ether, then 100mL of 4% NaOH and shaking for 6minutes. Fierz-David [Chimia 1 246 1947] shook 1L of ether with 10g of a zinc-copper couple. (This reagent is prepared by suspending zinc dust in 50mL of hot water, adding 5mL of 2M HCl and decanting after 20seconds, washing twice with water, covering with 50mL of water and 5mL of 5% cuprous sulfate with swirling. The liquid is decanted and discarded, and the residue is washed three times with 20mL of ethanol and twice with 20mL of diethyl ether). Aldehydes can be removed from diethyl ether by distillation from hydrazine hydrogen sulfate, phenyl hydrazine or thiosemicarbazide. Peroxides and oxidisable impurities have also been removed by shaking with strongly alkaline-saturated KMnO4 (with which the ether was left to stand in contact for 24hours), followed by washing with water, conc H2SO4, water again, then drying (CaCl2) and distillation from sodium, or sodium containing benzophenone to form the ketyl. Other purification procedures include distillation from sodium triphenylmethide or butyl magnesium bromide, and drying with solid NaOH or P2O5. [Beilstein 1 IV 1314.] Rapid purification: Same as for 1,4-dioxane.

Toxicity evaluation

Inhalation is the main route of exposure to diethyl ether. Occupational exposure to diethyl ether may occur through inhalation and dermal contact with this compound at workplaces where diethyl ether is used. Exposure to this chemical may also occur via inhalation of ambient air and ingestion of contaminated drinking water. Although rare, intentional (suicidal) exposure is also reported.
The industrial use of diethyl ether may result in its release to the environment through various waste streams. In air, diethyl ether will exist as a vapor and will be degraded in the atmosphere after reacting with hydroxyl and nitrate radicals. Halflives of these reactions in air are estimated to be 1.2 and 5.8 days, respectively. In soil and water, diethyl ether is expected to volatilize and biodegradation is likely to be a slow process. Bioconcentration of diethyl ether in aquatic organisms is low.

Incompatibilities

May form explosive mixture with air. Incompatible with strong acids; strong oxidizers halogens, sulfur, sulfur compounds, causing fire and explosion hazard. Can form peroxides from air, heat, sunlight; may explode when container is unstoppered or otherwise opened. Attacks some plastics, rubber and coatings. Being a nonconductor, chemical may accumulate static electric charges that may result in ignition of vapor.

Waste Disposal

Concentrated waste containing no peroxides-discharge liquid at a controlled rate near a pilot flame. Concentrated waste containing peroxidesperforation of a container of the waste from a safe distance followed by open burning. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal