Introduction to 1-methyl-2-pyrrolidone

Alias name: N-methylpyrrolidone

More aliases :N-Me thylpy rrolidone NMP

Molecular formula :C5HOON

Molecular weight :99, 13

Physical property data

1, properties: colorless transparent oily liquid, slightly amine smell.

2, density (g/mL,25/25C):1, 0260

3, relative vapor density (g/mL, air =1):3, 4

4, melting point (°C):-24, 4

5, boiling point C℃, atmospheric pressure):204

6, boiling point (DEG.1, 87 k Pa):84, 5

7, refractive index (25 ° C):1, 468

8. Viscosity (mPa-s) : 1.65

9, flash point (℃):95

10. Ignition point (° C):346

11, heat of evaporation (KJ/kg,b, p,):439, 5

12, heat of combustion (KJ/mol):3010

13. Critical temperature (° C):445

14, critical pressure (MPa):4, 76

15, conductivity (S/m, 25℃:(1~2)x10-8

16, vapor pressure (kPa, 150℃):21, 60

17, vapor pressure (kPa, 100℃):3, 20

18, vapor pressure (kPa, 78~79°C):1, 33

19, vapor pressure (kPa 60℃):0, 53

20, solubility: easily soluble in water, ethanol, ether, acetone, ethyl acetate, chloroform and benzene, can dissolve most organic and inorganic compounds, polar gases, natural and synthetic polymer compounds.

Use

1, in the pharmaceutical industry, 1-methyl-2-pyrrolidone is mainly used for the preparation of broad spectrum antibiotic Cefepime (Cefepine). Other uses are also very wide, such as the extraction of aromatic hydrocarbons from lubricating oil; Acetylene recovery and refining; Gas alkenes and dialkenes are refined; Polymer solvent, etc.

2, N methylpyrrolidone (NMP) is a polar aprotic transfer solvent. It has low toxicity, high boiling point and outstanding solubility. Strong selectivity and good stability. Widely used in aromatics extraction, acetylene, olefin, diolefin purification, polyvinylidene fluoride solvent, lithium ion battery electrode auxiliary materials, syngas desulfurization, lubricating oil refining, lubricating oil antifreeze agent,

Olefin extractant, solvent obtained during polymerization of insoluble engineering plastics, agricultural herbicides, insulation materials, integrated circuit production, semiconductor industry precision instruments, circuit boards to wash, PVC exhaust recycling, cleaning agents, dye additives, dispersants, etc. It is also used for polymers to obtain solvents and polymerization reaction media, such as engineering plastics and aramid fibers. In addition, it can also be used in pesticides, medicine and cleaning agents.

3, excellent advanced solvent, widely used in petrochemical, pesticide, medicine, electronic materials and other fields. It can be used for syngas desulfurization, lubricating oil refining, lubricating oil antifreeze agent, olefin extraction agent, agricultural herbicide, insulation material, integrated circuit production, PVC tail gas recovery, cleaning agent, dye additives, dispersant and so on.

4, is polyamide, polyester, polyurethane, acrylic resin and other excellent solvent. Widely used in polymer synthesis, refining, synthetic fiber spinning, coating, plastic surface treatment and so on. It is also used as a solvent and dispersant for pesticides, paints and pigments, and as a cleaning agent for precision instruments. Also used for acetylene, butadiene separation, recovery, aromatics extraction and so on.

5, boiling point, flash point high, large dissolution capacity, used for precision instrument cleaning agent. In detergents, it can be used as air freshener, automotive and industrial cleaning agent, fabric softener, floor dewaxing agent, floor brightener, stove cleaner, hard surface cleaner, glass cleaner, paint remover, fabric soap, carpet stain remover, bathroom cleaner. Strong dissolving ability, is the preferred solvent for paint remover, household chemicals and processing solvents. As a co-solvent,NMP can improve the brightness of the ground brightener. Due to its high solubility and low volatility, it can be used in automotive and industrial cleaning agents together with other solvents such as alkanes, terpenes, propylene carbonate and propylene glycol ether series solvents. It is also used in metal component cleaning processes to replace 1,1, 1-trichloroethane. It can be recycled by distillation, has good biodegradability and is non-toxic to aquatic organisms.

Property and stability

1, colorless liquid, ammonia taste, this product is less toxic. It can be miscible with water and soluble in most organic solvents such as ether and acetone. It can dissolve most organic and inorganic compounds, polar gases, natural and synthetic polymer compounds.

2, chemical properties: relatively stable in neutral solution. In 4% sodium hydroxide solution, 50% to 70% hydrolysis occurs after 8 hours. It is gradually hydrolyzed in concentrated hydrochloric acid to form 4-methylaminobutyric acid CH3NH(CH2)3COOH. Due to the carbonyl reaction, ketone or pyrrolidone can be formed,

3, in the presence of alkali catalyst and olefin, alkylation reaction occurs at the third position. N-methylpyrrolidone is weakly basic and can form hydrochloride. Adducts are formed with heavy metal salts, such as nickel bromide heated to 150 ° C to form NiBr2(C5H9ON)3 with a melting point of 105 ° C.

Storage method

Store under dry, inert gas, keep the container sealed, and store in a cool, dry place.

Synthesis method

1. It is obtained by the reaction of y monobutyrolactone with methylamine. The first step of the reaction is that y-butyrolactone and methylamine produce 4-hydroxy-n-methylbutanamide, and the second step is to dehydrate to produce N-methylpyrrolidone. The two-step reaction can be carried out continuously in a tubular reactor, with the molar ratio of y-butyrolactone to methylamine being 1:1 and 15, the pressure is about 6MPa, and the temperature is 250C. After the reaction is complete, the finished product is concentrated and distilled under pressure. The yield is 90%. If the reactor is used for production, the amount of methylamine is 1, 5-2, 5 times the theoretical amount, taking laboratory preparation as an example. 2moly-butyrolactone and 4 moles of liquid methylamine were added to a 500ml autoclaver, heated in a closed enclosure, and kept at 280°C for 4h. After cooling, excessive methylamine is released, distilled, and coke is reduced to 201-202°C fractions, about 180g of product is obtained, and the yield is about 90%. Raw material consumption (kg/g) Y-butyrolactone 980 methylamine (40%)860

Refining method: N-methylpyrrolidone and benzene azotrope distillation or add molecular sieve placed for several days to remove water, and then with a column height of 100cm, filled with glass spiral distillation column for vacuum distillation, collect the middle fraction.

2. V-butyrolactone reacts with methylamine, cools after the reaction, removes excess methylamine and water to concentrate the product, and then distillate under vacuum.