Pyrrolidine

Pyrrolidine
Names
	Preferred IUPAC name Pyrrolidine
	Other names Azolidine; Azacyclopentane; Tetrahydropyrrole; Prolamine
Identifiers
CAS Number	123-75-1 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:33135 ;
ChEMBL	ChEMBL22830 ;
ChemSpider	29008 ;
ECHA InfoCard	100.004.227
PubChem CID	31268;
RTECS number	UX9650000;
UNII	LJU5627FYV ;
CompTox Dashboard (EPA)	DTXSID3059559 ;
	InChI InChI=1S/C4H9N/c1-2-4-5-3-1/h5H,1-4H2 Key: RWRDLPDLKQPQOW-UHFFFAOYSA-N ; InChI=1/C4H9N/c1-2-4-5-3-1/h5H,1-4H2 Key: RWRDLPDLKQPQOW-UHFFFAOYAX;
	SMILES C1CCNC1;
Properties
Chemical formula	C4H9N
Molar mass	71.123 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),; 19.56 (pKa of conjugate acid in acetonitrile)
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	highly flammable, harmful, corrosive, possible mutagen
NFPA 704 (fire diamond)	3 3 1
Flash point	3 °C (37 °F; 276 K)
Autoignition; temperature	345 °C (653 °F; 618 K)
Safety data sheet (SDS)	MSDS
Related compounds
Related Nitrogen heterocyclic compounds	Pyrrole (aromatic with two double bonds); Pyrroline (one double bond); Pyrrolizidine (two pentagonal rings)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) 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. It has a characteristic semen-like odor.^[4] Compared to acyclic secondary amines, it is about 10 times more basic.

Synthesis and occurrence

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

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]

References

^ Hall, H. K. (1957). "Correlation of the Base Strengths of Amines". Journal of the American Chemical Society. 79 (20): 5441–5444. doi:10.1021/ja01577a030.
^ 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.
^ MSDS
^ Journal of Chemical Ecology September 1975, Volume 1, Issue 3, pp 299–310], Specific Anosmia to 1-Pyrrolidine
^ 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
^ R. B. Woodward, I. J. Pachter, and M. L. Scheinbaum (1974). "2,2-(Trimethylenedithio)cyclohexanone". Organic Syntheses. 54: 39{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 6, p. 1014.

[1] Hall, H. K. (1957). "Correlation of the Base Strengths of Amines". Journal of the American Chemical Society. 79 (20): 5441–5444. doi:10.1021/ja01577a030.

[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.

[3] MSDS

[4] Journal of Chemical Ecology September 1975, Volume 1, Issue 3, pp 299–310], Specific Anosmia to 1-Pyrrolidine

[Ullmann-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". Organic Syntheses. 54: 39{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 6, p. 1014.

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