PRODUCTS

2-PYRROLIDONE

CAS:   616-45-5
MF:   C4H7NO
MW:   85.1
EINECS:   210-483-1

Synonyms
2-Pyrrolidone Butyrolactam;2-AZACYCLOPENTANONE;2-P;2-KETOPYRROLIDINE;ALPHA-PYRROLIDONE;PIPERIDINIC ACID LACTAM;2-Oxopyrrolidine;2-Pyrol

2-Pyrrolidinone is the simplest member of the class of pyrrolidin-2-ones, consisting of pyrrolidine in which the hydrogens at position 2 are replaced by an oxo group.
The lactam arising by the formal intramolecular condensation of the amino and carboxy groups of gamma-aminobutyric acid (GABA).
2-Pyrrolidinone has a role as a polar solvent and a metabolite.
2-Pyrrolidone, also known as 2-pyrrolidinone or butyrolactam, is an organic compound consisting of a 5-membered lactam, making it the simplest γ-lactam.
2-Pyrrolidinone is a colorless liquid that is miscible with water and most common organic solvents.
2-Pyrrolidone itself and it various derivatives, especially N-methylpyrrolidone, have a variety of industrial uses.

2-Pyrrolidinone Chemical Properties
Melting point: 23-25 °C (lit.)
Boiling point: 245 °C (lit.)
density: 1.12 g/mL at 25 °C (lit.)
vapor density: 2.9 (vs air)
vapor pressure: 0.04 hPa (20 °C)
FEMA: 4829 | 2-PYRROLIDONE
refractive index: n20/D 1.487(lit.)
Fp: >230 °F
storage temp.: 2-8°C
solubility H2O: miscible (completely)
form: Liquid
pka: 16.62±0.20(Predicted)
color: Clear colorless to pale yellow
PH: 9-11 (100g/l, H2O, 20℃)
explosive limit: 1.8-16.6%(V)
biological source: synthetic
Water Solubility: miscible
Sensitive: Hygroscopic
Merck: 14,8016
BRN: 105241
Stability: Hygroscopic
InChI: 1S/C4H7NO/c6-4-2-1-3-5-4/h1-3H2,(H,5,6)
InChIKey: HNJBEVLQSNELDL-UHFFFAOYSA-N
LogP: -0.71 at 20℃
Surface tension: 46.31mN/m at 293.15K
CAS DataBase Reference: 616-45-5(CAS DataBase Reference)
NIST Chemistry Reference: 2-Pyrrolidinone(616-45-5)
EPA Substance Registry System: 2-Pyrrolidinone (616-45-5)

Chemical Properties
2-Pyrrolidinone occurs as a colorless or slightly grayish liquid, as white or almost white crystals, or colorless crystal needles.
2-Pyrrolidinone has a characteristic odor.
Miscible with water, alcohol, ether, chloroform, benzene, ethyl acetate and carbon disulfide, insoluble in petroleum ether.

Uses
2-Pyrrolidinone is a widely used organic polar solvent for various applications.
2-Pyrrolidinone is also an intermediate in the manufacture of polymers.
2-pyrrolidone widely exists in various physiologically active natural products in nature.
For example, 2-Pyrrolidinone is the main structural unit of gonadotropin releasing hormone.
At the same time, 2-pyrrolidone is an important raw material and intermediate of medicine, pesticide, dye, peptide and other chemicals.
If 2-Pyrrolidinone is used as the end chain of peptide, it also plays a stable role in the conformation of the compound.
Many polysubstituted 2-pyrrolidones have been used in the synthesis and production of a variety of drugs and applied for patents.
2-Pyrrolidone itself is used in inkjet cartridges.
A variety of pharmaceutical drugs are 2-pyrrolidone derivatives, including cotinine, doxapram, and ethosuximide, and the racetams.
The chemical is an intermediate in the production of the polyvinylpyrrolidone precursor vinylpyrrolidone.

Pharmaceutical Applications
2-Pyrrolidinone and N-methylpyrrolidone are mainly used as solvents in veterinary injections.
2-Pyrrolidinone has been shown to be a better solubilizer than glycerin, propylene glycol, or ethanol.
They have also been suggested for use in human pharmaceutical formulations as solvents in parenteral, oral, and topical applications.
In topical applications, pyrrolidones appear to be effective penetration enhancers.
2-Pyrrolidinone have also been investigated for their application in controlled-release depot formulations.

Industrial uses
2-Pyrrolidone is used as an intermediate for synthesis of l-vinyl-2-pyrrolidone and various TV-methylol derivatives used as textile-finishing agents; as a solvent for various polymers, chlordane and DDT, d-sorbitol, glycerin, and sugars; and as a decolorizing agent for kerosene, fatty oils, and rosins.
N-methyl-2-pyrrolidone and 2-Pyrrolidinone are utilized in petroleum refining to selectively extract aromatics from paraffinic hydrocarbons.
2-Pyrrolidinone is used as a plasticizer and coalescing agent for acrylic latices and acrylic/styrene copolymers in emulsion coatings, i.e. floor waxes.
A linear high molecular weight polyamide polymer of 2-pyrrolidone, nylon-4, is used as a textile fiber, injection molding compound, and film-forming polymer.

Production Methods
The synthesis of 2-pyrrolidone was first reported in 1889 as the product of dehydration of 4-aminobutanoic acid.
2-Pyrrolidinone is produced commercially by condensation of butyrolactone with ammonia, a method first described in 1936.
Other synthetic routes include carbon monoxide insertion into allylamine, hydrolytic hydrogenation of succinonitrile, and hydrogenation of ammoniacal solutions of maleic and succinnic acids.
2-Pyrrolidinone is prepared from butyrolactone by a Reppe process, in which acetylene is reacted with formaldehyde.

Reactions
2-Pyrrolidinone undergoes the reactions of a typical lactam, e.g. ring opening, attack on the carbonyl group, and replacement of hydrogens alpha to the carbonyl group.
Strong acids and bases catalyze the hydrolysis of 2-pyrrolidone to 4-aminobutanoic acid (GABA).
The hydrogen atom on the nitrogen atom is easily replaced by alkylation reactions with alkyl halide or sulfates, or reaction with acid anhydrides, acyl halides, ethylene oxide, and styrene.
Condensation reactions with secondary amines and alcohols, and O-alkylation reactions occur at the carbonyl group.
In the presence of anionic catalyst systems, 2-Pyrrolidinone is polymerized to polypyrrolidone, nylon-4.

Production
2-Pyrrolidinone is produced industrially almost exclusively by treating aqueous gamma-butyrolactone with ammonia at a temperature of 250–290 °C and pressures ranging from 0.4–1.4 MPa over solid magnesium silicate catalysts.
The reaction is carried out in a tubular reactor which is packed with the solid catalyst.
The latter is arranged as a fixed bed and the reaction is carried out in the vapor phase.
Product yields of 75–85% are reached.
After subsequent distillation and purification, the desired 2-Pyrrolidinone is obtained with a purity of 99.5%.
Alternative routes include the catalytic or electrochemical reduction of succinimide, the carbonylation of allylamine, the hydrogenation of succinonitrile under hydrolytic conditions, and the reaction of maleic or succinic anhydride in aqueous ammonia with Pd–Ru-catalysts.
In 2010, the worldwide demand for 2-Pyrrolidinone was estimated to be 32.000 t.
Important manufacturers of 2-pyrrolidone are BASF and ISP (International Speciality Products, now Ashland Inc.).