Pyrrolidine

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Pyrrolidine
Pyrrolidine svg.svg Pyrrolidine3d.png
Identifiers
CAS number 123-75-1 YesY
PubChem 31268
ChemSpider 29008 YesY
UNII LJU5627FYV YesY
ChEBI CHEBI:33135 YesY
ChEMBL CHEMBL22830 YesY
RTECS number UX9650000
Jmol-3D images Image 1
Properties
Molecular formula C4H9N
Molar mass 71.12 g mol−1
Appearance Clear colorless liquid
Density 0.866 g/cm3
Melting point −63 °C (−81 °F; 210 K)
Boiling point 87 °C (189 °F; 360 K)
Solubility in water Miscible
Acidity (pKa) 11.27 (pKa of conjugate acid in water),[1]

19.56 (pKa of conjugate acid in acetonitrile)[2]

Hazards
MSDS MSDS
R-phrases R11-R20/21/22-R34[3]
S-phrases S16-S26-S28-S36/37-S45
Main hazards highly flammable, harmful, corrosive, possible mutagen
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasoline) Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 3 °C (37 °F; 276 K)
Related compounds
Related Nitrogen heterocyclic compounds Pyrrole (aromatic with two double bonds)
Pyrroline (one double bond)
Pyrrolizidine (two pentagonal rings)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Pyrrolidine, also known as tetrahydropyrrole, is an organic compound with the molecular formula (CH2)4NH. It is a cyclic secondary amine, also classified as a saturated heterocycle. It is a colourless liquid that is miscible with water and most organic solvents with a characteristic semen-like odor.[4] Compared to acyclic secondary amines, it is about 10 times more basic.

Synthesis and occurrence[edit]

Pyrrolidine is produced industrially by treatment of 1,4-butanediol with ammonia over an oxide catalyst.[5]

Pyrrolidine is found in the leaves of tobacco and carrot. The pyrrolidine ring structure is present in numerous natural alkaloids such as nicotine and hygrine. It is found in many pharmaceutical drugs such as procyclidine and bepridil. It also forms the basis for the racetam compounds (e.g. piracetam, aniracetam). The amino acids proline and hydroxyproline are, in a structural sense, derivatives of pyrrolidine.

Nicotine contains an N-methylpyrrolidine ring linked to a pyridine ring.

Applications[edit]

Pyrrolidine is used as a building block in the synthesis of more complex compounds. In organic chemistry, pyrrolidine is used to activate ketones and aldehydes toward nucleophilic addition by formation of enamines:[6]

Enamine.png

References[edit]

  1. ^ Hall, H. K. (1957). "Correlation of the Base Strengths of Amines". Journal of the American Chemical Society 79 (20): 5441. doi:10.1021/ja01577a030.  edit
  2. ^ Kaljurand, I.; Kütt, A.; Sooväli, L.; Rodima, T.; Mäemets, V.; Leito, I.; Koppel, I. A. (2005). "Extension of the Self-Consistent Spectrophotometric Basicity Scale in Acetonitrile to a Full Span of 28 pKa Units:  Unification of Different Basicity Scales". The Journal of Organic Chemistry 70 (3): 1019–1028. doi:10.1021/jo048252w. PMID 15675863.  edit
  3. ^ MSDS
  4. ^ Journal of Chemical Ecology 1 (3): 299–310. 
  5. ^ Karsten Eller, Erhard Henkes, Roland Rossbacher, Hartmut Höke "Amines, Aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a02_001
  6. ^ R. B. Woodward, I. J. Pachter, and M. L. Scheinbaum (1974), "2,2-(Trimethylenedithio)cyclohexanone", Org. Synth. 54: 39 ; Coll. Vol. 6: 1014