2,2,6,6-Tetramethylpiperidine
[CAS# 768-66-1]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Lactone and oxygen-containing heterocyclic compound >> Thiazole, thiophene and pyridine
• Name: 2,2,6,6-Tetramethylpiperidine
• Synonyms: HTMP
• Molecular Formula: C₉H₁₉N
• Molecular Weight: 141.25
• CAS Registry Number: 768-66-1
• EC Number: 212-199-3
• SMILES: CC1(CCCC(N1)(C)C)C

Properties

• Density: 0.837
• Boiling point: 152 °C
• Refractive index: 1.443-1.446
• Flash point: 24 °C
• Water solubility: MISCIBLE

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS06;GHS07 Danger
• Risk Statements: H226-H301-H302-H314-H315-H319-H332-H335
• Safety Statements: P210-P233-P240-P241-P242-P243-P260-P261-P264-P264+P265-P270-P271-P280-P301+P316-P301+P317-P301+P330+P331-P302+P352-P302+P361+P354-P303+P361+P353-P304+P340-P305+P351+P338-P305+P354+P338-P316-P317-P319-P321-P330-P332+P317-P337+P317-P362+P364-P363-P370+P378-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	3	H301
Acute toxicity	Acute Tox.	4	H302
Skin corrosion	Skin Corr.	1A	H314
Acute toxicity	Acute Tox.	4	H332
Serious eye damage	Eye Dam.	1	H318
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Skin corrosion	Skin Corr.	1C	H314
Acute toxicity	Acute Tox.	3	H302
Skin corrosion	Skin Corr.	1B	H314
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Flammable liquids	Flam. Liq.	2	H225
Skin irritation	Skin Irrit.	2	H314
Acute toxicity	Acute Tox.	3	H331
Eye irritation	Eye Irrit.	2A	H319

• Transport Information: UN 1992

Discovery and Applications

2,2,6,6-Tetramethylpiperidine, often abbreviated as TMP or TMAP, was first synthesized and studied in the mid-20th century as part of research into the chemistry of piperidines. It is a branched-chain tertiary amine with the molecular formula C9H19N. The discovery of 2,2,6,6-Tetramethylpiperidine expanded the understanding of piperidine derivatives and provided chemists with a versatile building block for organic synthesis.

2,2,6,6-Tetramethylpiperidine and its derivatives are utilized in pharmaceutical synthesis as intermediates and chiral auxiliaries. They serve as precursors for the production of active pharmaceutical ingredients (APIs) and are essential in the synthesis of complex molecules with specific biological activities.

In the agrochemical sector, 2,2,6,6-Tetramethylpiperidine derivatives are employed in the synthesis of herbicides, insecticides, and fungicides. These compounds play a crucial role in pest control and crop protection, enhancing agricultural productivity.

2,2,6,6-Tetramethylpiperidine is used as a catalyst and scavenger in polymerization reactions. It helps control the molecular weight and structure of polymers and can act as a chain transfer agent to regulate polymerization kinetics.

2,2,6,6-Tetramethylpiperidine is utilized as a solvent in various chemical processes and formulations. It serves as a polar, aprotic solvent suitable for dissolving a wide range of organic and inorganic compounds.

2,2,6,6-Tetramethylpiperidine is employed as a base in organic synthesis reactions, particularly in the formation of C-N bonds and as a deprotonating agent. It facilitates various transformations, including nucleophilic substitution, elimination, and condensation reactions.

2,2,6,6-Tetramethylpiperidine derivatives are used as photoinitiators in photopolymerization processes. They initiate polymerization reactions upon exposure to light, leading to the formation of cross-linked polymer networks in coatings, adhesives, and dental materials.

2,2,6,6-Tetramethylpiperidine derivatives are employed as corrosion inhibitors in metalworking fluids, lubricants, and cooling systems. They form protective films on metal surfaces, preventing corrosion and extending the lifespan of machinery and equipment.

References

2024. Boryl radical-mediated halogen-atom transfer enables arylation of alkyl halides with electrophilic and nucleophilic coupling partners. Nature Synthesis, 3(9).
DOI: 10.1038/s44160-024-00587-5

1962. Retention of free valence in the reduction of the 2,2,6,6-tetramethyl-γ-piperidonenitroxide radical by the Kizhner method. Bulletin of the Academy of Sciences of the USSR, Division of chemical science, 11(12).
DOI: 10.1007/bf00911387

1964. Polarographic study of certain N-oxide free radicals. Bulletin of the Academy of Sciences of the USSR, Division of chemical science, 13(8).
DOI: 10.1007/bf00850350