Hazardous diethyl ether

Highly Hazardous diethyl ether, benzene, chloroform, DCF, nitromethane... 

This reaction is the cause of a widely recognized laboratory hazard. The peroxides formed from several commonly used ethers, such as diethyl ether and tetrahydrofuran, are explosive. Appreciable amounts of such peroxides can build up in ether samples that have been exposed to the atmosphere. Because the hydroperoxides are less volatile than the ethers, they are concentrated by evaporation or distillation, and the concentrated peroxide solutions may explode. For this reason, extended storage of ethers that have been exposed to oxygen is extremely hazardous. 

Industrially, chlorine is obtained as a by-product in the electrolytic conversion of salt to sodium hydroxide. Hazardous reactions have occuned between chlorine and a variety of chemicals including acetylene, alcohols, aluminium, ammonia, benzene, carbon disulphide, diethyl ether, diethyl zinc, fluorine, hydrocarbons, hydrogen, ferric chloride, metal hydrides, non-metals such as boron and phosphorus, rubber, and steel. 

Ethers — (R-O-R) are low on the scale of chemical reactivity. Aliphatic ethers are generally volatile, flammable liquids with low boiling points and low flashpoints. Well known hazardous ethers include diethyl ether, dimethyl ether, tetrahydrofuran. Beyond their flammability, ethers present an additional hazard they react with atmospheric oxygen in the presence of light to form organic peroxides. 

Rapid-acting dermally hazardous cytotoxin that inhibits protein synthesis and affects clotting factors in the blood. It is capable of producing incapacitating or lethal effects. T2 is obtained from various molds and fungi (Fusarium sp.). It is a colorless crystalline solid of white powder that melts at 304°F. Impure samples may be a colorless to slightly yellow oil. It is slightly soluble in water, but soluble in ethyl acetate, acetone, ethanol, chloroform, methylene chloride, diethyl ether, and dimethyl sulfoxide (DMSO). It is heat stable and can be stored at room temperature for years. 

Peroxidizable hazard on concentration Diethyl ether Tetrahydrofuran Dioxane Acetal... 

Some chemicals are susceptible to peroxide formation in the presence of air [10, 56]. Table 2.15 shows a list of structures that can form peroxides. The peroxide formation is normally a slow process. However, highly unstable peroxide products can be formed which can cause an explosion. Some of the chemicals whose structures are shown form explosive peroxides even without a significant concentration (e.g., isopropyl ether, divinyl acetylene, vinylidene chloride, potassium metal, sodium amide). Other substances form a hazardous peroxide on concentration, such as diethyl ether, tetrahydrofuran, and vinyl ethers, or on initiation of a polymerization (e.g., methyl acrylate and styrene) [66]. 

What are the hazards associated with the use of diethyl ether and what specific precautions are taken ... 

Fat includes triglycerides, sterols, lecithins (phospholipids), essential oils, fat-soluble pigments such as chlorophyll, and similar substances. The AOAC recommends that anhydrous diethyl ether kept over freshly cut sodium pieces is used for the extractant (Padmore, 1990, p. 79), but we prefer to use petroleum spirit, also called light petroleum and petroleum ether, with a boiling range of 40-60°C, as it is a less hazardous solvent. 

The initial medicinal chemistry route for the early syntheses of sildenafil required -1540 kg solvent/kg API. After four years of development, a modified chemical route and process led to a 93.9% reduction in the total amount of solvent used. The continued optimization of the sildenafil process as it went into commercial production further reduced the amount of solvent used from 94 to 19 kg solvent/kg API. Several highly hazardous solvents were also eliminated from the production scheme including DCM, methanol, and diethyl ether. Upon implementation of solvent recovery, the total amount of solvent required was only 5 kg solvent/kg API produced [17, 20]. The final commercial route used only 0.32% of the total solvent used for the initial synthesis. 

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