2,6-Lutidine
[CAS# 108-48-5]

Identification

• Classification: Organic raw materials >> Heterocyclic compound
• Name: 2,6-Lutidine
• Synonyms: 2,6-Dimethylpyridine
• Molecular Formula: C₇H₉N
• Molecular Weight: 107.15
• CAS Registry Number: 108-48-5
• EC Number: 203-587-3
• FEMA: 3540
• SMILES: CC1=NC(=CC=C1)C

Properties

• Density: 0.9252
• Melting point: -6 °C
• Boiling point: 143-145 °C
• Refractive index: 1.4966-1.4986
• Flash point: 33 °C
• Water solubility: 40 g/100 mL (20 °C)

Safety Data

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

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Flammable liquids	Flam. Liq.	3	H226
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1C	H314
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	4	H312
Eye irritation	Eye Irrit.	2A	H319
Acute toxicity	Acute Tox.	4	H332

• Transport Information: UN 1993

Discovery and Applications

2,6-Lutidine (C7H9N), also known as 2,6-lutidine, is a heterocyclic organic compound first discovered in coal tar fractions. It belongs to the family of pyridine isomers, characterized by two methyl groups attached to the pyridine ring at the 2 and 6 positions. The discovery of 2,6-lutidine dates back to the late 19th century, when chemists were extensively studying coal tar components to separate and understand various aromatic compounds.

2,6-Lutidine is a colorless liquid with a characteristic pungent odor. It has a boiling point of about 144°C and is slightly soluble in water, but is readily soluble in organic solvents such as ethanol, ether, and chloroform. The presence of methyl groups at the 2 and 6 positions of the pyridine ring makes it less reactive than pyridine itself, but it has unique stereo and electronic properties that are valuable in various chemical reactions.

2,6-Lutidine is widely used as a base and catalyst in organic synthesis. Its relatively low nucleophilicity compared to pyridine makes it an ideal base for reactions that require deprotonation but not nucleophilic attack. It is used as a catalyst in Friedel-Crafts acylation and other reactions that require mild basic conditions to promote carbon-carbon or carbon-heteroatom bond formation.

In the pharmaceutical industry, 2,6-lutidine is a valuable reagent and intermediate for the synthesis of active pharmaceutical ingredients (APIs) and intermediates. Its role as a base aids in the formation of a variety of pharmacologically active compounds. It is also used for the protection and deprotection of functional groups during multistep organic synthesis, ensuring that specific reactions occur without interference from other reactive sites in the molecule.

2,6-Lutidine plays a role in polymer chemistry as a catalyst for the polymerization of certain monomers, helping to produce specialty polymers with specific properties.

In coordination chemistry, 2,6-lutidine is used as a ligand that is able to donate electron density through the nitrogen atom, making it a useful ligand for the formation of metal complexes. These complexes are studied for their catalytic, magnetic, and electronic properties.

2,6-Lutidine is a staple in chemical research laboratories, and due to its alkalinity and solubility, it is used as an analytical reagent in a variety of chemical assays and titrations. Its unique properties make it a subject of study for the development of new chemical reactions and materials.

2,6-Lutidine is a flammable liquid that can be a health hazard if not handled properly. It can cause skin and eye irritation, and inhalation of its vapors can lead to respiratory irritation. When handling this chemical, appropriate personal protective equipment (PPE) such as gloves, goggles, and adequate ventilation must be worn to minimize the risk of exposure.

Although 2,6-Lutidine is not considered to be very toxic to the environment, it should still be properly managed to prevent contamination. Waste disposal and discharge should be controlled according to regulatory guidelines to minimize environmental impact.

References

2015. Two-step one-pot synthesis of dihydropyrazinones as Xaa-Ser dipeptide isosteres through morpholine acetal rearrangement. Organic & Biomolecular Chemistry.
DOI: 10.1039/c5ob00783f

2013. Synthesis, characterisation and biological activities of [(p-cym)RuX(pz4lut)]n+ and [{(p-cym)RuX}2(μ-pz4lut)]n+ (X = Cl, H2O and pz4lut = α,α,α′,α′-tetra(pyrazol-1-yl)-2,6-lutidine). Dalton Transactions.
DOI: 10.1039/c3dt51275d

1953. [The bromination of 2-picoline, 4-chloro-2-picoline and 4-chloro-2,6-lutidine by means of N-bromosuccinimide]. Pharmaceutical Bulletin.
DOI: 10.1248/cpb1953.1.293