2,2,6,6-Tetramethylpiperidine
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Names | |||
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Preferred IUPAC name
2,2,6,6-Tetramethylpiperidine | |||
Other names
Norpempidine
Tetramethylpiperidine | |||
Identifiers | |||
3D model (JSmol)
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Abbreviations | TMP | ||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard | 100.011.090 | ||
EC Number |
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PubChem CID
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UNII | |||
CompTox Dashboard (EPA)
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Properties | |||
C9H19N | |||
Molar mass | 141.254 g/mol | ||
Appearance | Clear liquid | ||
Density | 0.83 g/mL | ||
Melting point | −59 °C (−74 °F; 214 K) | ||
Boiling point | 152 °C (306 °F; 425 K) | ||
Hazards | |||
GHS labelling: | |||
Danger | |||
H226, H301, H302, H314, H315, H319, H332, H335 | |||
P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P280, P301+P310, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P321, P330, P332+P313, P337+P313, P362, P363, P370+P378, P403+P233, P403+P235, P405, P501 | |||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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2,2,6,6-Tetramethylpiperidine, abbreviated TMP, HTMP, or TMPH, is an organic compound of the amine class. In appearance, it is a colorless liquid and has a "fishy", amine-like odor. This amine is used in chemistry as a hindered base (hindered amine). Although TMP finds limited use per se, its derivatives are a mainstay of hindered amine light stabilizers.
TMP is the starting material for an even stronger base, lithium tetramethylpiperidide and the radical species TEMPO. Another non-nucleophilic base is N,N-diisopropylethylamine. Its aqueous pKaH (conjugate acid dissociation constant, a measure of basicity) is 11.07 at 25 °C,[1] while its pKa (acid dissociation constant, a measure of acidity) is approximately 37.[2]
Preparation
[edit]Many routes for the synthesis of TMP have been reported. One method[3] starts with a conjugate addition reaction of ammonia to phorone. The intermediate triacetone amine is then reduced in a Wolff-Kishner reaction.
See also
[edit]- 2,6-Dimethylpiperidine
- Pempidine
- TEMPO ((2,2,6,6-Tetramethylpiperidin-1-yl)oxyl)
References
[edit]- ^ William M. Haynes, ed. (2015). CRC handbook of chemistry and physics : a ready-reference book of chemical and physical data (96th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4822-6096-0. OCLC 910908643.
- ^ Reich, Hans (2022). "Bordwell pKa table".
- ^ Detlef Kampmann; Georg Stuhlmüller; Roger Simon; Fabrice Cottet; Frédéric Leroux; Manfred Schlosser (2005). "A Large-Scale Low-Cost Access to the Lithium 2,2,6,6-Tetramethylpiperidide Precursor". Synthesis. 2005 (6): 1028–1029. doi:10.1055/s-2004-834856. S2CID 93476763.