2,3-Difluoro-5-chloropyridine
[CAS# 89402-43-7]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridine compound >> Chloropyridine
• Name: 2,3-Difluoro-5-chloropyridine
• Synonyms: 5-chloro-2,3-difluoropyridine
• Molecular Formula: C₅H₂ClF₂N
• Molecular Weight: 149.53
• CAS Registry Number: 89402-43-7
• EC Number: 410-090-7
• SMILES: C1=C(C=NC(=C1F)F)Cl

Properties

• Density: 1.44 g/mL
• Melting point: 47-49 °C
• Boiling point: 135 °C
• Refractive index: 1.4738
• Flash point: 48 °C

Safety Data

• Hazard Symbols: GHS02;GHS07 Warning
• Risk Statements: H226-H302-H412
• Safety Statements: P210-P233-P240-P241-P242-P243-P264-P270-P273-P280-P301+P317-P303+P361+P353-P330-P370+P378-P403+P235-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute toxicity	Acute Tox.	4	H302

Discovery and Applications

2,3-Difluoro-5-chloropyridine is a chemical compound belonging to the class of halogenated pyridines. Its molecular formula is C5H2ClF2N, featuring a pyridine ring substituted with chlorine and two fluorine atoms. The systematic study and synthesis of this compound have opened new avenues in various industrial and scientific fields, particularly in pharmaceuticals and agrochemicals.

The development of 2,3-Difluoro-5-chloropyridine can be traced back to the ongoing research into fluorinated organic compounds, which have been of significant interest due to their unique chemical properties and potential applications. The presence of fluorine atoms in organic molecules often imparts improved metabolic stability, enhanced binding affinity in biological systems, and increased chemical robustness. These attributes make fluorinated compounds attractive candidates for drug development and other applications.

The synthesis of 2,3-Difluoro-5-chloropyridine typically involves the selective halogenation of pyridine derivatives. One common method includes the reaction of 2,3-difluoropyridine with chlorinating agents under controlled conditions to achieve the selective chlorination at the desired position. Advanced techniques in organic synthesis, including catalytic and electrophilic substitution reactions, have further refined the production process, ensuring higher yields and purity.

In the pharmaceutical industry, 2,3-Difluoro-5-chloropyridine serves as a crucial intermediate in the synthesis of various bioactive compounds. Its unique structure, characterized by the presence of both chlorine and fluorine atoms, allows for the modulation of biological activity and the optimization of pharmacokinetic properties. Fluorinated compounds often exhibit enhanced membrane permeability and resistance to metabolic degradation, making them valuable in drug design.

Specifically, 2,3-Difluoro-5-chloropyridine has been explored in the development of antiviral, antibacterial, and anticancer agents. Its ability to serve as a building block in complex organic synthesis enables the creation of molecules with improved efficacy and safety profiles. Researchers have leveraged its chemical reactivity to introduce functional groups that enhance target specificity and minimize off-target effects.

Beyond pharmaceuticals, 2,3-Difluoro-5-chloropyridine is also significant in the agrochemical sector. It is employed in the synthesis of herbicides, insecticides, and fungicides, contributing to crop protection and increased agricultural productivity. The compound’s structural features help in designing agrochemicals that are more effective against pests and diseases while being environmentally benign.

The halogenation of pyridine rings in agrochemicals can lead to compounds with prolonged activity and reduced volatility, thereby enhancing their efficacy and reducing the frequency of application. Moreover, the introduction of fluorine atoms can improve the environmental stability of these chemicals, making them more resistant to degradation by sunlight and microbial action.

The discovery and application of 2,3-Difluoro-5-chloropyridine underscore the importance of halogenated pyridines in modern chemistry. Its synthesis has paved the way for advancements in pharmaceuticals and agrochemicals, demonstrating the compound’s versatility and significance. As research continues, the potential for new and improved applications of 2,3-Difluoro-5-chloropyridine remains vast, promising further contributions to science and industry.

References

2014. Synthesis of Fluorinated Pyridines. Fluorine in Heterocyclic Chemistry, Volume 2.
DOI: 10.1007/978-3-319-04435-4_1

2010. Nucleophilic Substitutions of Nitroarenes and Pyridines: New Insight and New Applications. Synthesis, 2010(20).
DOI: 10.1055/s-0029-1218810

1996. Synthesis of halogenopyridines (review). Chemistry of Heterocyclic Compounds, 32(9).
DOI: 10.1007/bf01164704