N-Methylpyrrolidone; N-Methylpyrrolidinone; NMP; 1-Methyl-2-pyrrolidone; Pharmasolve
|Jmol 3D model||Interactive image|
|Molar mass||99.13 g·mol−1|
|Melting point||−24 °C (−11 °F; 249 K)|
|Boiling point||202 to 204 °C (396 to 399 °F; 475 to 477 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
N-Methyl-2-pyrrolidone (NMP) is an organic compound consisting of a 5-membered lactam. It is a colorless liquid, although impure samples can appear yellow. It is miscible with water and with most common organic solvents. It also belongs to the class of dipolar aprotic solvents such as dimethylformamide and dimethyl sulfoxide. It is used in the petrochemical and plastics industries as a solvent, exploiting its nonvolatility and ability to dissolve diverse materials.
NMP is produced industrially by a typical ester-to-amide conversion, by treating butyrolactone with methylamine. Alternative routes include the partial hydrogenation of N-methylsuccinimide and the reaction of acrylonitrile with methylamine followed by hydrolysis. About 20,000 to 30,000 tons are produced annually.
NMP is used to recover certain hydrocarbons generated in the processing of petrochemicals, such as the recovery of 1,3-butadiene and acetylene. It is used to absorb hydrogen sulfide from sour gas and hydrodesulfurization facilities. Due to its good solvency properties NMP is used to dissolve a wide range of polymers. It is also used as a solvent for surface treatment of textiles, resins, and metal coated plastics or as a paint stripper. It is utilized as a solvent in the commercial preparation of polyphenylene sulfide. In the pharmaceutical industry, N-methyl-2-pyrrolidone is used in the formulation for drugs by both oral and transdermal delivery routes. It is also used heavily in lithium ion battery fabrication, as a solvent for electrode preparation, though there is much effort to replace it with solvents of less environmental concern, like water.
NMP is on the list of Chemicals Known to the State to Cause Cancer or Reproductive Toxicity cited in California Proposition 65 (1986). In the face of increasing regulation, some manufacturers are considering alternative solvents for some applications, especially where worker exposure is difficult to control, such as in paint stripping, graffiti removal, and agriculture. On the other hand, NMP biodegrades readily and has low toxicity to aquatic life.
In the limited studies with humans, "direct contact of skin with NMP caused redness, swelling, thickening, and painful vesicles when NMP was used as a cleaner or as a paint stripper" while extensive rat studies showed that exposure led to irritation, weight changes, apathy, reproductive harm, birth defects, and mortality depending on the level and method of exposure. 
- Albrecht Ludwig Harreus, R. Backes, J.-O. Eichler, R. Feuerhake, C. Jäkel, U. Mahn, R. Pinkos, R. Vogelsang"2-Pyrrolidone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, 2011, Weinheim. doi:10.1002/14356007.a22_457.pub2
- "Pharmasolve® Drug Solubilizer" (PDF). PharmaGuide. International Specialty Products, a division of Ashland Inc.: Page 9. Retrieved 2012-06-06.
- "Production of batteries made cheaper and safer, thanks to Finnish researchers". Science Daily. Retrieved 7 May 2015.
- "List of Chemicals as Known to the State of California to Cause Cancer or Reproductive Toxicity" (PDF). California OEHHA. Retrieved 4 December 2012.
- Reisch, Mark (July 21, 2008). "Solvent users look to replace NMP". Chemical & Engineering News: 32.
- "WHO Concise International Chemical Assessment Document 35" (PDF). World Health Organization. Retrieved 9 March 2016.