1. Acetic anhydride method dimethylamine and acetic anhydride have acylation reaction at 0-20 ℃, and then neutralized with low temperature liquid removing acetic, isolated from sodium acetate and Neutralization Solution and alkali washing, distillation, boiling range 164-166.5 DEG C fraction for the finished product. Material consumption fixed: acetic anhydride (95%) 1150kg/t, dimethylamine (40%) 1898kg/t.
2. Acetyl chloride method, by the reaction of dimethylamine and chloride, can also be prepared in dimethylacetamide. Compared with the process of the current domestic acetic anhydride process, it can reduce production costs, and improve economic efficiency.
3. Acetic acid method Fushun Research Institute of Chemical equipment using acetic acid and dimethylamine synthesis, and achieved good results. The process is characterized by the use of advanced catalytic distillation technology, strengthen reaction, reduce energy consumption, separation and product yield greatly improved, simplified the process. Compared to the synthesis process of this technology and two methylacetamide acetic anhydride methods, it can reduce production costs, improve economic benefits. China is currently more of people use it.
4. Study abroad Oxo trimethylamine and carbon monoxide carbonylation synthesis to produce N,N-dimethylacetamide approach. The reaction with iron, cobalt, nickel iodide or bromide as a catalyst.
Air & Water Reactions
N,N-dimethylacetamide dimethyl amine, also known as an acetyl group, an acetyl dimethylamine, referred to as the DMAC, which 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..
Invasive dangerous situation
Inhaled toxic (toxicity stronger than dimethylformamide), decomposition products may be absorbed through the skin, eye, skin and mucous membranes, which have a strong irritant. See "dimethylformamide." Combustible. Rat oral LD505.4ml/kg. The allowable concentration in air is US 10ppm (35mg/m3).
Flammability hazard characteristics
In case of fire, high temperature, strong oxidants combustible; combustion emissions of toxic nitrogen oxide fumes.
Oral-rat LD50: 4300 mg/kg; Oral-Mouse LD50: 4620 mg/kg
The N, N-Dimethylacetamide are incompatible wiyb carbon tetrachloride and other halogenated compounds. Unsaturated aliphatic compounds are soluble in this product, but saturated aliphatic solubility of the compound in this product is small. The solubility of hydrolysis product is small. But in the presence of acid, it can accelerate the hydrolysis. This product has good stability, and it does not decompose during distillation. With a strong base to form acetates and alkyl amines, in the presence of a proton, the alcohol can have solution when heated.
- Used in organic synthesis, also used as solvents, catalysts, and paint removers.
- DMAC is mainly used as synthetic fibers (acrylonitrile) and polyurethane spinning synthetic polyamide resin and a solvent, but also it is used for separating styrene from the C8 fraction extractive distillation solvent, and it is widely used in the aspects of polymer films, coatings and medicine. Currently it is used to synthesize a large number of antibiotics and pesticides in the pharmaceutical and pesticide. The catalyst can also be used for the reaction, electrolytic solvent, paint scavengers and various crystalline solvent adducts and complexes.
- Used as the reaction solvent of pharmaceutical synthesis, synthetic fiber spinning solvents and synthetic resins, photographic chemicals chromogenic agent solvents, paints and other solvents, catalyst.
Skin-Rabbit 10 mg/24 hr mild; Eye-rabbit mild 100 mg
Steam inhalation, skin absorption, ingestion, contact with the eyes and skin.
The workers, who are often exposed to dimethyl acetamide, observed jaundice, liver damage, but in general it can be quickly restored. When someone with FDA uses it as anticancer drugs and large doses of oral symptoms, it can cause depression, lethargy, visual hallucinations. It may also occur heart, kidney and brain degeneration. DMA mouse embryo has toxic effects on the rabbit have teratogenic effects.
Measured in the air: adsorption with silica, methanol and analyzed by gas chromatography.
ChEBI: 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.
Transparent colorless liquid. The organic solvent can be mixed with any water, alcohol, ether, ester, benzene, chloroform, and aromatic compounds.
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.
TLV-TWA 10 PPM (35 mg/cubic meter); STEL 15 PPM (50 mg/m3)
Solvent for many organic reactions and in industrial applications.
Storage with iron costumes to prevent the mechanical damage. Store in a cool, dry place, avoid light exposure, away from any possible source of ignition.
colourless liquid with a faint ammonia odour
Liquid causes mild irritation of eyes and skin. Ingestion causes depression, lethargy, confusion and disorientation, visual and auditory hallucinations, perceptual distortions, delusions, emotional detachment, and affective blunting.
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.]
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.
N,N-dimethylacetamide Department are toxic flammable liquids, adjustment shall be toxic substances provides storage and transportation. Transportation shall be marked "dangerous drugs" mark, and prevent the sun, impact, when handling, attention gently on the container.
Recommended methods of controlling waste incineration (incinerators shall have a scrubber or thermal means to reduce the discharge of NOx).
N,N-Dimethylacetamide is combustible.
Workshop should be ventilated, confined to production equipment. At high vapor concentrations work place, you should use an organic vapor respirator or air supplied respirator, gloves and protective clothing to prevent absorption through the skin. Wear goggles to prevent splashing into the eyes. In the workplace with splashing or spills of this substance, you should be taken off the wet clothes immediately and thoroughly wash the contaminated surface of the skin. Distribute to workers clean clothes before going to work every day, and take a shower after work.
Foam, powder, carbon dioxide
Explosive hazardous characteristics
Mixed with air can be explosive
When the pre-employment and periodic medical examinations, we should pay special attention to the skin, the central nervous system, liver disease or liver function tests.
If such chemicals like splashed into the eyes, you should rinse with running water 15min immediately; if contact with skin, you should wash it immediately with plenty of water; if they are swallowed, you should be given medical attention, clothing with plenty of water, induce vomiting, gastric lavage. Do not induce vomiting with unconscious person. Instead, they should be sent to the hospital at once.