Outline
N,N-Dimethylacetamide is a highly polar aprotic solvent, micro ammonia odor, very strong dissolving power, soluble wide, miscible with water, aromatics, esters, ketones, alcohols, ether, benzene and chloroform and other arbitrary and enable activation of molecular compounds. It is widely used as a solvent and a catalyst. The solvent, with high boiling point, flash point, thermal stability and chemical stability of the solvent, is used for polyacrylonitrile spinning solvent, synthetic resin and natural resins, formic acid vinyl ester resin, vinyl pyridine copolymer and aromatic carboxylic acid. The catalyst can be used in the process of urea heating to produce the reaction of cyanide, sodium halide and metal cyanide to produce the reaction of alkyl acetylene, organic halide and isocyanate. N,N-dimethylacetamide also can be used as electrolytic solvent and photography with coupler solvent, de paint agent, organic synthesis of raw materials, pesticide and pharmaceutical raw materials. Separation of styrene from C8 fraction, extraction, distillation, solvent, etc.
Chemical Properties
N,N-Dimethylacetamide (DMA) is a transparent colorless liquid. The organic solvent can be mixed with any water, alcohol, ether, ester, benzene, chloroform, and aromatic compounds. It has a very good solvency for many resins and polymers. It is used in the production of acrylic fibers, films, sheets, and coatings, and as a reaction medium and intermediate in organic syntheses.
Uses
N,N-Dimethylacetamide is used as a polar solvent in organic synthesis as well as in reactions involving strong bases such as sodium hydroxide. It is also used as a solvent for fibers like polyacrylonitrile, spandex, as an excipient in drugs viz. vumon, busulfex and in the adhesive industry. It finds application as a reaction medium in the production of pharmaceuticals, agrochemicals, dyes and plasticizers. It is widely used in polymer industry due to its high solving power for high molecular-weight polymers and synthetic resins. It plays an important role as a catalyst in various reactions viz. cyclization, halogenation, cynidation, alkylation and dehydrogenation and increases the yield of main products. It is also used as an extracting agent for oil and gases, in paint removers, in the production of photo-resist stripping compounds and as booster solvent in coatings.
Production method
Dimethylacetamide has been produced by the reaction of acetic acid with dimethylamine (Siegle, 1980).
Description
Dimethylacetamide (DMAC) is a synthetic organic compound
that is produced from a reaction of dimethylamine and acetic
acid or acetic anhydride. It is a colorless to yellow liquid with
a faint odor resembling ammonia. DMAC has similar density
to water and is miscible with water and organic substances. This
organic compound is commonly associated with many industrial
uses, either as a starting material or an intermediate.
DMAC is a good solvent that is used in polymer dissolution,
especially in the fiber industry. Historically, DMAC was also
tested as a possible antineoplastic agent in a phase 1 study
involving 17 patients. However, liver and central nervous
system (CNS) toxicity associated with DMAC was observed and
these patients had altered mental states, resulting in no further
drug development.
Chemical Properties
Dimethylacetamide occurs as a clear, colorless, slightly hygroscopic liquid with a weak ammonia-like or fish-like odor. odor threshold concentration is 46.8 ppmv (Leonardos et al., 1969). It is soluble in a wide variety of solvents.
Uses
N,N-dimethylacetamide is an excellent solvent and often acts as a catalyst in halogenation, cyclization, and alkylation reactions. It is an important industrial solvent for polyacrylonitrile, vinyl resins, cellulose derivatives, styrene polymers and linear polyesters. It is also used in all analytical laboratories as a major component of mobile phase in High Performance Liquid Chromatography (HPLC) and in Liquid Chromatography - Mass Spectrometry (LC-MS). N,N-dimethylacetamide lithium chelate complexes intercalate cationic sites in layered silicates.
Application
N,N-Dimethylacetamide is primarily used as an industrial solvent and intermediate in the manufacture of pharmaceuticals, fine chemicals, agrochemicals, polymers, and resins. It is also used as a spinning solvent in the production of fibers of various polymers, including acrylic, polyurethane, polyurea copolymer, and meta-aramid. Moreover, this aprotic dipolar solvent is also used in X-ray and photographic products and in the production of polyimide films. The polyimide films are produced for a variety of industries, including consumer electronics, solar photovoltaic and wind energy, aerospace, automotive, and industrial applications. N,N-Dimethylacetamide has other minor uses, including removal of ink, stripping of paint, and also for laboratory use.
Definition
ChEBI: N,N-dimethylacetamide is a member of the class of acetamides that is acetamide in which the hydrogens attached to the N atom have been replaced by two methyl groups respectively. Metabolite observed in cancer metabolism. It has a role as a human metabolite. It is a member of acetamides and a monocarboxylic acid amide. It is functionally related to an acetamide.
Preparation
N,N-Dimethylacetamide is prepared by reaction of dimethylamine with acetic acid, acetic anhydride, or acetate esters. Heating dimethylamine acetate with, or without a catalyst affords N,N-Dimethylacetamide. Reaction of dimethylamine with acetate esters requires a catalyst; sodium methoxide is typically used.
General Description
Dimethylacetamide appears as a clear colorless liquid with a faint odor similar to ammonia. About the same density as water. Flash point 145°F. Vapors heavier than air. May by toxic by skin absorption. May irritate eyes and skin.
Air & Water Reactions
Water soluble.
Reactivity Profile
N,N-Dimethylacetamide is an amide. Incompatible with oxidizing agents and halogenated compounds. Exothermic reactions occur with carbon tetrachloride and hexachlorocyclohexane. N,N-Dimethylacetamide can react violently in the presence of iron. Special Hazards of Combustion Products: Emits carbon oxides, nitrogen oxides, and dimethylamine when heated to decomposition.
Health Hazard
A study of 41 workers who had been exposed to dimethylacetamide from 2 to 10 years revealed the occurrence of disorders reflecting liver damage (Corsi, 1971). Retention of bromosulfophthalein was increased in 9 of 10 workers who had been exposed to dimethylacetamide for 7 to 10 years, and in 10 of 20 workers who had been exposed to dimethylacetamide for 2 to 7 years. Other parameters of hepatic function which were altered in the exposed individuals include proteinemia, cholesterolemia, activities of hepatic transaminases and alkaline phosphatase in serum, and bilirubinemia. Hepatomegaly was diagnosed in 14 workers.
In a clinical trial, dimethylacetamide was administered to patients with advanced malignancies and caused abnormal mental states (Weiss et al 1962a, b). This effect was observed at a dose of 400 mg/kg given daily for 3 or more days.
The symptoms were not seen at 300 mg/kg or lower. The second or third dose caused depression, lethargy, occasional confusion or disorientation. The fourth or fifth dose produced striking hallucinations, perceptual distortions and delusions in all nine patients. All patients reverted to normal several days after discontinuation of treatment with dimethylacetamide.
Fire Hazard
N,N-Dimethylacetamide is combustible.
Industrial uses
Dimethylacetamide is a powerful industrial solvent, the uses of which are very similar to those of dimethylformamide (Siegle, 1980). Its strong solvent action renders it particularly useful in the manufacture of films and fibers and as a solvent for polyacrylonitrile, polyvinyl chloride, polyamides, cellulose derivatives and polystyrenes and in coatings and adhesive formulations. Dimethylacetamide dissolves many inorganic salts.
Safety Profile
Moderately toxic by
skin contact, inhalation, intravenous, and
intraperitoneal routes. Mildly toxic by
ingestion. Experimental teratogenic and
reproductive effects. A skin and eye irritant.
Less toxic than dimethylformamide.
Mutation data reported. Combustible when
exposed to heat and flame. A moderate
explosion hazard. Violent reaction with
halogenated compounds (e.g., carbon
tetrachloride, hexachlorocyclohexane) when
heated above 9OOC. Iron powder catalyzes
the reaction so that it initiates at 71OC.
When heated to decomposition it emits
toxic fumes of NOx
Safety
Dimethylacetamide is used in pharmaceutical preparations as a solvent in parenteral formulations and is generally regarded as a nontoxic material when used as an excipient. Animal toxicity studies indicate that dimethylacetamide is readily absorbed into the bloodstream following inhalation or topical application. Repeated exposure to dimethylacetamide may be harmful and can result in liver damage. High intravenous doses (>400mg/kg/day for 3 days) may be hallucinogenic.
LD50 (rabbit, SC): 9.6g/kg(11) LD50 (rat, IP): 2.75g/kg LD50 (rat, IV): 2.64g/kg LD50 (rat, oral): 4.93g/kg LD50 (mouse, inhalation): 7.2g/kg LD50 (mouse, IP): 2.8g/kg
Potential Exposure
Drug,Mutagen; Reproductive Effector; Primary Irritant.Dimethylacetamide is used primarily as a solvent for synthetic and natural resins, especially acrylic fibers and spandex. About 15% of dimethylacetamide production is used tomake alkyl (C12-14) dimethylamine oxide (a surfactant) andrubber chemicals. Dimethylacetamide is also used as anextraction solvent for butadiene manufacture.
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 CPRif heart action has stopped. Transfer promptly to amedical facility. When this chemical has been swallowed,get medical attention. Give large quantities of water andinduce vomiting. Do not make an unconscious personvomit.
Carcinogenicity
DMAC was not carcinogenic in
rats administered 100, 300, or 1000 mg/kg/day in drinking
water for 2 years. Rats and mice were exposed by
inhalation to 0, 25, 100, or 350 ppm DMAC for 6 h/day,
5 days/week for 18 months (mice) or 2 years (rats). DMAC
was not oncogenic under these conditions in either the rat or
the mouse.
Environmental Fate
Chemical/Physical. Releases toxic fumes of nitrogen oxides when heated to decomposition (Sax
and Lewis, 1987).
Metabolism
33 mg or 92 mg of 14C-labelled DMAC were given by gavage to two rats. The major urinary components were:60-70% MMAC, 7-10% N -hydroxymethylacetamide, 7- 10%, Acetamide and some residual DMAC. A small proportion of DMAC and its intermediates was hydrolysed and eliminated as Carbon Dioxide.
Twenty male rats were given two subcutaneous injections of 300 mg DMAC, MMAC and Acetamide were found in the urine.
20 rats had 20-80% DMAC solutions (0.12 ml) applied to their backs. The amount of MMAC increased as the solution concentration increased. Recovery ranged from 13% for the 20% solution to 42% for undiluted DMAC (Du Pont, 1988).
These studies show that the major metabolic pathway of DMAC "in vivo" in rats is sequential N-demethylation and elimination from the body.
https://hpvchemicals.oecd.org/ui/handler.axd?id=16564422-daff-4489-8c27-735d3ab0b260
storage
Dimethylacetamide should be stored in an airtight container, protected from light, in a cool, dry place. Dimethylacetamide has an almost unlimited shelf-life when kept in closed containers and under nitrogen. It is combustible.
Shipping
This material is not covered in DOT’sPerformance-Oriented Packaging Standards. It may,however, be classified as a combustible liquid, n.o.s. Thisclass requires no shipping label. It falls in Hazard Class 3[each reference to a Class 3 material is modified to read“COMBUSTIBLE LIQUID” when that material is reclassified in accordance with y173.150 (e) or (f) of this subchapter or has a flash point above 60.5℃/141°F but below93℃/200°F] and Packing Group III. The symbol “D” identifies proper shipping names which are appropriate fordescribing materials for domestic transportation but may beinappropriate for international transportation under the provisions of international regulations (e.g., IMO, ICAO). Analternate proper shipping name may be selected when eitherdomestic or international transportation is involved.
Purification Methods
Shake the amide with BaO for several days, reflux it with BaO for 1hour, then fractionally distil it under reduced pressure. Store it over molecular sieves. [Beilstein 4 IV 180.]
Toxicity evaluation
Little data on the metabolism of DMAC are available in the
literature. Hepatotoxicity of DMAC is believed to be metabolism
dependent. From its metabolic activation (by cytochrome
P450s and probably CYP2E1), reactive species and free radical
metabolites are produced and readily attack the heme prosthetic
group of the liver, leading to suicidal hepatic enzyme
inactivation.
Incompatibilities
Dimethylacetamide is incompatible with carbon tetrachloride, oxidizing agents, halogenated compounds, and iron. It attacks plastic and rubber. Contact with strong oxidizers may cause fire.
Regulatory Status
Included in the FDA Inactive Ingredients Database (IM injections, IV injections and infusions). Included in parenteral medicines licensed in the UK.
