ГЕКСАМЕТИЛФОСФОРНЫЙ ТРИАМИД

Химические свойства

colourless or light amber liquid with an aromatic spicy odour

Использование

Hexamethylphosphoramide is a dipolar co-solvent and an effective additive used in reactions like reduction of halides, deoxygenation of sulfones, halide olefin couplings and cleavage of carbon-sulfur bond.

Общее описание

Clear colorless to light amber liquid with a spicy odor.

Реакции воздуха и воды

Water soluble.

Профиль реактивности

Hexamethylphosphoramide may react with strong oxidizing agents and strong acids . Susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.

Опасность

Possible carcinogen. Toxic by skin contact. Combustible.

Угроза здоровью

The acute toxicity of hexamethylphosphoramide is low. HMPA can cause irritation upon contact with the skin and eyes. Hexamethylphosphoramide has been found to cause cancer in laboratory animals exposed by inhalation and meets the criteria for classification as an OSHA "select carcinogen." Chronic exposure to HMPA can cause damage to the lungs and kidneys. Reproductive effects in male animals treated with hexamethylphosphoramide have been observed. HMPA should be regarded as a substance with poor warning properties.

Пожароопасность

Hexamethylphosphoramide is combustible.

Воспламеняемость и взрывоопасность

Combustible liquid. Its decomposition at high temperatures or in a fire can produce phosphine, phosphorus oxides, and oxides of nitrogen, which are extremely toxic. Carbon dioxide or dry chemical extinguishers should be used for HMPA fires.

Возможный контакт

Hexamethylphosphoric triamide is a material possessing unique properties and is widely used as a solvent in small quantities, in organic and organometallic reactions in laboratories. This is the major source of occu pational exposure to HMPA in the United States. It is also used as a processing solvent in the manufacture of aramid fibers. HMPA has been evaluated for use as an ultraviolet light absorber or inhibitor in polyvinylchloride formulations; as an additive for antistatic effects; as a flame retardant; and as a deicing additive for jet fuels. Hexamethylphosphoric triamide has also been extensively investigated as an insect chemosterilant.

Канцерогенность

Hexamethylphosphoramide is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.

хранилище

this compound should be handled only in a fume hood, using appropriate impermeable gloves and splash goggles to prevent skin and eye contact. Containers of this substance should be stored in secondary containers.

Перевозки

UN3082 Environmentally hazardous substances, liquid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous haz ardous material, Technical Name Required

Методы очистки

The industrial synthesis is usually by treatment of POCl3 with excess of dimethylamine in isopropyl ether. Impurities are water, dimethylamine and its hydrochloride. It is purified by refluxing over BaO or CaO at about 4mm pressure in an atmosphere of nitrogen for several hours, then distilled from sodium at the same pressure. The middle fraction (b ca 90o) is collected, refluxed over sodium under reduced pressure under nitrogen and distilled. It is kept in the dark under nitrogen, and stored in solid CO2. It can also be stored over 4A molecular sieves. Alternatively, it is distilled under vacuum from CaH2 at 60o and is crystallised twice in a cold room at 0o, seeding the liquid with crystals obtained by cooling in liquid nitrogen. After about two-thirds are frozen, the remaining liquid is drained off [Fujinaga et al. Pure Appl Chem 44 117 1975]. For tests of purity see Fujinaga et al. in Purification of Solvents, Coetzee Ed., Pergamon Press, Oxford, 1982. For efficiency of desiccants in drying HMPA see Burfield and Smithers [J Org Chem 43 3966 1978, Sammes et al. J Chem Soc, Faraday Trans 1 281 1986]. [Beilstein 4 IV 284.] CARCINOGEN.

Несовместимости

Incompatible (possibly violent reaction; fire and explosions) with oxidizers (chlorates, nitrates,peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.). Keep away from alkaline materials, chemi cally active metals, strong acids, strong bases.

Утилизация отходов

Excess hexamethylphosphoramide and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution's waste disposal guidelines.