680-31-9 Usage
General description
Hexamethylphosphoramide is made from the reaction of dimethylamine and phosphorus oxychloride. It has a molecular weight of 179.2, appearing as colorless or light yellow transparent liquid with slightly astringent taste. It has a relative density of 1.0253~1.0257 (20 ℃), refractive index of 1.4582~1.4589 (20 °C), the freezing point of 2~7 °C and the boiling point of 116~117 °C (1480Pa). It is soluble in polar and non-polar solvents. It is also miscible with the commonly used plasticizers such as dioctyl phthalate, dioctyl sebacate, and triphenyl phosphite in any proportion. It has a similar toxicity to phosphate. Avoid contact with skin. Its containers should be tightly sealed to prevent leakage and water absorption to be deteriorated Hexamethylphosphoramide is the light stabilizer of the PVC, enabling an excellent anti-aging properties of outdoor products with excellent weather resistance, therefore being known as highly-efficient weathering agent of PVC.
Addition of 2 to copies of this product to the PVC film can significantly improve both the weather resistance and cold resistance as well as reducing the processing temperature by 10 °C. This product can also be used as the excellent polar solvent of many kinds of polymer materials such as polyphenylene sulfide, polyurethane and polyamide for improving the resin quality, simplifying the process and reducing costs. Addition it into the ethylene-propylene rubber can improve the flexibility and oil resistance. It can also be used as a co-catalyst for the polymerization of propylene to improve the catalytic efficiency of the main catalyst.
Harmful effects and symptoms of poisoning
To animals: Hexamethylphosphoramide (HMPA) is known to have various kinds of toxic effects on experimental animals. HMPA-induced acute poisoning in rats is characterized with nephropathy, severe bronchiectasis and bronchial pneumonia. Application of HMPA repetitively to rabbit skin can lead to weight loss, changes in gastric function and apparent neurological disorders. Rats subjecting to oral administration of HMPA can exhibit testicular atrophy and semen deficiencies. Small chickens subjecting to oral administration of HMPA can also get highly inhibited growth in its testis. HMPA has been known to induce mutagenesis in Drosophila. However, the effects of HMPA on sex chromosomes in mice showed that the frequency of chromosome aberration induced by HMPA was not significant compared with the control group. Preliminary results of the toxicity study upon inhaling HMPA revealed that nasal tumors will appear in rats after 8 months after being exposed to 400 to 4000 ppb HMPA. In some diseased mice, cancer initiated from the epithelium connecting the nasal bone can fill the nasal cavity and penetrates into the brain. Rats exposed to 50 ppb HMPA didn’t develop nasal cancer compared with the control group.
To humans: the role of HMPA on human toxicity has not been reported.
Protective measures
The traditional measure is that the operator should wear protective clothing, wearing protective glasses and gloves, to avoid direct contact with the product with the production site should be well ventilated.
Chemical properties
It appears as colorless transparent flammable liquid with a medium ammonia flavor. It is soluble in water, polar and non-polar solvents.
Uses
Different sources of media describe the Uses of 680-31-9 differently. You can refer to the following data:
1. 1.?? It can be used as the efficient anti-corrosion agent of PVC and other kinds of chlorine-containing resin products and coatings.
2.?? The product is the weathering solvent of polyvinyl chloride and excellent polar solvent, having a significant effect on the low temperature resistance and aging resistance of the agricultural film; it is a multi-functional high-boiling polar solvent that is aprotic. It can be used as the solvents of polymer synthesis with special effect on the synthesis of polyphenylene sulfide and aromatic polyamide and so on. This product, as the co-catalyst of propylene polymerization catalyst, when supplied to the ethylene propylene rubber, can improve the missile and oil resistance of the latter one. Hexamethylphosphoramide can also be used as a gas chromatographic fixative, ultraviolet inhibitor, rocket fuel additives for lowering the freezing point and chemical sterilizers.
3.?? It is effective non-proton solvent; as fixative of gas chromatography (highest usage temperature: 35°C with methanol as the solvent); used for separation and analysis of hydrocarbons; for separation of alkanes, alkenes and alkynes; accelerator of stereo-specific reaction; Ultraviolet inhibitor of PVC.
2. Aprotic solvent in organic synthesis. Solvent for polymers, gases; polymerization catalyst; thermal stabilizer in polystyrene; protective additive for polyvinyl and polyolefin resins against uv light degradation. De-icing additive for jet fuels. Chemosterilant for a number of insect pests; chemical mutagen.
3. Solvent for polymers; polymerization
catalyst; stabilizer against thermal degradation
in polystyrene; UV stabilizer in polyvinyl and
polyolefin resins
4. 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.
Production method
It can be obtained through the reaction between dimethylamine and alkali chlorophosphorus. Put the dimethylamine and phosphorus oxychloride for reaction in triethylene glycol as the solvent; control the temperature at 40-60 °C; upon reaction, add ammonia as acid-binding agent with interaction with the generated hydrogen chloride to become ammonium chloride precipitation. After completion of the reaction, filtration was performed. Recycle the trichlorethylene from the filtration and then perform alkali treatment, and then conduct distillation, collecting the fraction of 113-118 °C (2.0kPa) fractions to derive Hexamethylphosphoramide (HMPA). Tsinghua Unisplendour Group Corporation has cooperated with the production plant to develop a new solvent-free process that can achieve a product purity of 99.2% or more. The industrial hexamethylphosphoramide appears as colorless or light yellow transparent liquid. Catalyst grade content ≥ 99.5%; first-class grade ≥ 99.0%; second-class products ≥ 98.0%. Fixed consumption amount of raw materials: dimethylamine 2410kg/t, phosphorus oxychloride: 1610kg/t, liquid ammonia 430kg/t.
Chemical Properties
Different sources of media describe the Chemical Properties of 680-31-9 differently. You can refer to the following data:
1. colourless or light amber liquid with an aromatic spicy odour
2. Hexamethylphosphoric triamide is a colorless
liquid with a spicy odor.
General Description
Clear colorless to light amber liquid with a spicy odor.
Air & Water Reactions
Water soluble.
Reactivity Profile
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.
Hazard
Possible carcinogen. Toxic by skin contact.
Combustible.
Health Hazard
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.
Fire Hazard
Different sources of media describe the Fire Hazard of 680-31-9 differently. You can refer to the following data:
1. 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.
2. Hexamethylphosphoramide is combustible.
Flammability and Explosibility
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.
Potential Exposure
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.
Carcinogenicity
Hexamethylphosphoramide is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.
storage
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.
Shipping
UN3082 Environmentally hazardous substances,
liquid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous haz ardous material, Technical Name Required
Purification Methods
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.
Incompatibilities
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.
Waste Disposal
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.
Check Digit Verification of cas no
The CAS Registry Mumber 680-31-9 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 6,8 and 0 respectively; the second part has 2 digits, 3 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 680-31:
(5*6)+(4*8)+(3*0)+(2*3)+(1*1)=69
69 % 10 = 9
So 680-31-9 is a valid CAS Registry Number.
InChI:InChI=1/C6H18N3OP/c1-7(2)11(10,8(3)4)9(5)6/h1-6H3
680-31-9Relevant articles and documents
STUDIES OF THE REACTIONS OF TRIAMINOPHOSPHINES WITH α,β-UNSATURATED NITRILES
Hennawy, Ibtisam T.
, p. 2109 - 2115 (1994)
Tris(dialkylamino)phosphines IIIa and IIIb react with furfurylidenemalonitrile (Ia) and its thiophene analogue Ib to give a mixture of 1:1 adducts IV and V.Compounds IV have aminophosphonium dipolar ion structure, while compounds V are the ylide forms.The ratio of the products depends on the reaction conditions.Some reactions of IV and V are described.
-
Hartley et al.
, p. 303,305 (1951)
-
Experimental study of speciation and mechanistic implications when using chelating ligands in aryl-alkynyl Stille coupling
Espinet, Pablo,Gallego, Ana M.,Marcos-Ayuso, Guillermo,Martínez-Ilarduya, Jesús M.,Martin-Alvarez, Jose M.,Pe?as-Defrutos, Marconi N.
supporting information, p. 11336 - 11345 (2020/09/03)
Neutral palladium(ii) complexes [Pd(Rf)X(P-L)] (Rf = 3,5-C6Cl2F3, X = Cl, I, OTf) with P-P (dppe and dppf) and P-N (PPh2(bzN)) ligands have chelated structures in the solid-state, except for P-L = dppf and X = Cl, were chelated and dimeric bridged structures are found. The species present in solution in different solvents (CDCl3, THF, NMP and HMPA) have been characterised by 19F and 31P{1H} NMR and conductivity studies. Some [Pd(Rf)X(P-L)] complexes are involved in equilibria with [Pd(Rf)(solv)(P-L)]X, depending on the solvent and X. The ΔH° and ΔS° values of these equilibria explain the variations of ionic vs. neutral complexes in the range 183-293 K. Overall the order of coordination strength of solvents and anionic ligands is: HMPA ? NMP > THF and I-, Cl- > TfO-. This coordination preference is determining the complexes participating in the alkynyl transmetalation from PhCCSnBu3 to [Pd(Rf)X(P-L)] (X = OTf, I) in THF and subsequent coupling. Very different reaction rates and stability of intermediates are observed for similar complexes, revealing neglected complexities that catalytic cycles have to deal with. Rich information on the evolution of these Stille systems after transmetalation has been obtained that leads to proposal of a common behaviour for complexes with dppe and PPh2(bzN), but a different evolution for the complexes with dppf: this difference leads the latter to produce PhCCRf and black Pd, whereas the two former yield PhCCRf and [Pd(CCPh)(SnBu3)(dppe)] or [Pd(CCPh)(SnBu3){PPh2(bzN)}]. This journal is
Reactions of 1,1′-(azodicarbonyl)dipiperidine with organophosphorus reagents
Boulos, Leila S.,Abdel-Malek, Hoda A.,El-Sayed, Naglaa F.,Moharam, Maysa E.
experimental part, p. 225 - 237 (2012/03/26)
1,1′carbonyl)dipiperidine reacts with tris(dimethylamino)phosphine, trialkyl phosphites, phosphorus ylides, and Lawesson's reagents to give the phosphorodihydrazidic amide, oxadiazole, dihydropyridazine, ethylenic, and thicarbonyl products, respectively. The antibacterial and antifungal activities for the new compounds are reported. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Biological Evaluation.
General and mild preparation of 2-aminopyridines
Londregan, Allyn T.,Jennings, Sandra,Wei, Liuqing
scheme or table, p. 5254 - 5257 (2011/02/24)
A general and facile one-pot amination procedure for the synthesis of 2-aminopyridines from the corresponding pyridine-N-oxides is presented as a mild alternative to SNAr chemistry. A variety of amines and heterocyclic-N-oxides participate effectively in this transformation which uses the phosphonium salt, PyBroP, as a means of substrate activation.
