2-Picoline
[CAS# 109-06-8]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridine compound >> Methylpyridine
• Name: 2-Picoline
• Synonyms: 2-Methylpyridine
• Molecular Formula: C₆H₇N
• Molecular Weight: 93.13
• CAS Registry Number: 109-06-8
• EC Number: 203-643-7
• SMILES: CC1=CC=CC=N1

Properties

• Density: 0.9±0.1 g/cm³, Calc.^*, 0.943 g/mL (Expl.)
• Melting point: -70 ºC (Expl.)
• Index of Refraction: 1.501, Calc.^*, 1.5 (Expl.)
• Boiling Point: 127.5±3.0 ºC (760 mmHg), Calc.^*, 128-129 ºC (Expl.)
• Flash Point: 26.1 ºC, Calc.^*, 29 ºC (Expl.)
• Water solubility: MISCIBLE

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS06;GHS07 Danger
• Hazard Statements: H226-H332-H312-H302-H335-H319
• Precautionary Statements: P210-P233-P240-P241-P242-P243-P260-P261-P262-P264-P264+P265-P270-P271-P280-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-P337+P317-P361+P364-P362+P364-P363-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
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	3	H331
Acute toxicity	Acute Tox.	3	H311
Skin corrosion	Skin Corr.	1C	H314
Serious eye damage	Eye Dam.	1	H318
Eye irritation	Eye Irrit.	2A	H319

• Transport Information: UN 2313

Discovory and Applicatios

2-Picoline, also known as 2-methylpyridine, is a methylated derivative of pyridine. It is a colorless to yellow liquid with a characteristic odor and is highly soluble in water and organic solvents. The compound has been known since the 19th century, with early studies focusing on its isolation from coal tar and its structural characterization. Pyridine derivatives, including 2-picoline, have long been subjects of interest due to their presence in natural alkaloids and their diverse chemical applications.

The primary industrial production of 2-picoline involves the catalytic reaction of formaldehyde, acetaldehyde, and ammonia. This method provides an efficient and high-yielding route to obtaining 2-picoline, which serves as an essential building block in organic synthesis. Alternative synthesis routes include the dealkylation of more complex pyridine derivatives or direct alkylation of pyridine itself. Advances in catalysis have further improved production efficiency and selectivity, making 2-picoline widely available for various applications.

One of the most significant applications of 2-picoline is in the production of nicotinic acid (vitamin B3) and its amide derivative, nicotinamide. These compounds are crucial in human and animal nutrition and play an essential role in metabolism. The oxidation of 2-picoline using chemical or microbial processes leads to nicotinic acid, which is widely used in pharmaceuticals and food fortification. The pharmaceutical industry also utilizes 2-picoline as an intermediate in the synthesis of various active compounds, including anti-inflammatory and antimicrobial agents.

In addition to its role in pharmaceuticals, 2-picoline finds extensive use as a precursor in agrochemical manufacturing. It is a key starting material in the synthesis of various herbicides, insecticides, and fungicides. Its derivatives are incorporated into formulations that protect crops from pests and diseases, contributing significantly to modern agricultural practices. The compound's structural versatility allows it to be modified into highly effective bioactive molecules with targeted activity.

The chemical industry employs 2-picoline in the production of specialty chemicals, including surfactants, corrosion inhibitors, and rubber processing agents. Its ability to participate in diverse chemical reactions makes it an attractive raw material for synthesizing complex organic compounds. The polymer industry benefits from 2-picoline-based intermediates, which contribute to the production of high-performance resins and coatings. Additionally, it is used in the synthesis of dyes and pigments, providing stable and vibrant color properties to various materials.

Catalysis is another field where 2-picoline derivatives have demonstrated significant utility. Metal complexes incorporating 2-picoline ligands are used as catalysts in organic transformations, including hydrogenation, oxidation, and cross-coupling reactions. These catalytic systems improve reaction efficiency and selectivity, reducing energy consumption and waste generation in industrial processes.

In the laboratory, 2-picoline serves as a versatile reagent in organic synthesis. It acts as a nucleophilic base in various reactions, facilitating transformations that lead to more complex heterocyclic compounds. Its coordination ability with metal ions is also exploited in analytical chemistry, where it is used in spectrophotometric and chromatographic techniques for metal ion detection and quantification.

While 2-picoline has numerous beneficial applications, its handling requires careful attention due to its toxicity and flammability. Proper storage conditions and protective measures are necessary to minimize exposure risks in industrial and laboratory settings. Regulatory guidelines govern its use to ensure safety and environmental compliance in its production and application.

The extensive utility of 2-picoline across different industries highlights its significance as a fundamental chemical building block. Its role in pharmaceuticals, agriculture, specialty chemicals, catalysis, and laboratory research underscores its importance in scientific and industrial advancements. Continued research into its reactivity and potential applications is likely to further enhance its value in various fields.

References

2024. Exploring the host compound dynamics of 1,4-phenylene-bis(di-p-fluorophenylmethanol) in mixed pyridines. Journal of Inclusion Phenomena and Macrocyclic Chemistry, 104(9-10).
DOI: 10.1007/s10847-024-01264-y

2024. Assessment of the impact of smoke from thermal destruction of materials of different origins on soil health. Environmental Monitoring and Assessment, 196(11).
DOI: 10.1007/s10661-024-13235-4

2024. Facile and efficient synthesis of N-benzyl chitosan via a one-pot reductive amination utilizing 2-picoline borane. Polymer Journal, 56(10).
DOI: 10.1038/s41428-024-00933-6