диэтиловый эфир щавелевой кислоты химические свойства, назначение, производство
Химические свойства
colourless liquid
Использование
Diethyl oxalate is used to prepare active pharmaceutical ingredients (API), plastics and dyestuff intermediates. It is also used as a solvent for cellulose esters, ethers, resins, perfumes and lacquers for electronics. It is involved in the transesterification reaction with phenol to get dipheny oxalate. It is also involved in the Claisen condensation ketosteroids to prepare glyoxalyl derivatives. Further, it is used to prepare sym-1,4-diphenyl-1,4-dihydro-1,2,4,5-polytetrazine. In addition to this, it is utilized in the microemulsion synthesis of zinc oxide nanoparticles.
Методы производства
Diethyl oxalate is produced via esterification of ethanol and
oxalic acid. It is a preferred solvent for cellulose acetate and
nitrate.
Общее описание
A colorless liquid. Flash point 168°F. Slightly denser than water and insoluble in water. Hence sinks in water. May irritate skin and mucous membranes; may be mildly toxic by ingestion; may emit irritating fumes in a fire. Vapors are much heavier than air. Used as a solvent for plastics and in the manufacture of perfumes and pharmaceuticals.
Реакции воздуха и воды
Insoluble in water.
Профиль реактивности
Diethyl oxalate is an ester. Esters react with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction of esters with caustic solutions. Flammable hydrogen is generated by mixing esters with alkali metals and hydrides
Опасность
Toxic by ingestion, strong irritant to skin
and mucous membranes.
Угроза здоровью
TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Contact with molten substance may cause severe burns to skin and eyes. Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Пожароопасность
Combustible material: may burn but does not ignite readily. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.
Профиль безопасности
Poison by ingestion.
Flammable liquid when exposed to heat or
flame; can react with oxidzing materials. To
fight fire, use foam, CO2, dry chemical.
When heated to decomposition it emits
acrid smoke and fumes. See also
OXALATES and ESTERS.
Описание
диэтиловый эфир щавелевой кислоты бесцветная жидкость, обладающая слабым приятным запахом; мало растворим в воде; смешивается со спиртом, диэтиловым эфиром.
Химические свойства
Диэтилоксалат обладает значительной карбонильной активностью и не способен к самоконденсации. В связи с этим его часто используют в качестве ацилирующего агента при реакции с другими сложными эфирами и кетонами.
Безопасность
Лабораторное и аналитическое использова
синтез
щавелевая кислота + 2·этанол → (серная кислота) → диэтиловый эфир щавелевой кислоты + 2·вода
диэтиловый эфир щавелевой кислоты препаратная продукция и сырье
сырьё
препарат