2-Mercaptopyridine
[CAS# 2637-34-5]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridine compound >> Pyridine derivative
• Name: 2-Mercaptopyridine
• Synonyms: 2-Pyridinethiol; 2-Pyridyl mercaptan
• Molecular Formula: C₅H₅NS
• Molecular Weight: 111.16
• CAS Registry Number: 2637-34-5
• EC Number: 220-131-9
• SMILES: C1=CC(=S)NC=C1

Properties

• Water solubility: 50 g/L (20 °C)
• Density: 1.2±0.1 g/cm³, Calc.^*
• Melting point: 127-130 °C (Expl.)
• Index of Refraction: 1.598, Calc.^*
• Boiling Point: 194.0±13.0 °C (760 mmHg), Calc.^*
• Flash Point: 71.1±19.8 °C, Calc.^*

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

2-Mercaptopyridine is a sulfur-containing organic compound with the chemical formula C5H5NS. It is a colorless to pale yellow liquid at room temperature and has a characteristic odor. The molecule consists of a pyridine ring with a thiol (–SH) group attached to the second carbon atom, making it an important member of the thiol group family. It is known for its ability to form coordination complexes with metals, particularly with transition metals, due to the lone pair of electrons present on the sulfur atom.

The discovery of 2-mercaptopyridine dates back to the early 20th century when sulfur-containing organic compounds began to receive attention for their potential as ligands in metal complexes. As a compound, it is primarily synthesized by reacting pyridine with sulfur or sulfur-containing reagents, such as Lawesson's reagent or carbon disulfide. The sulfur atom in the thiol group plays a critical role in the reactivity and biological activity of 2-mercaptopyridine, making it an important target for synthetic and medicinal chemists.

One of the key applications of 2-mercaptopyridine is in the preparation of metal complexes. It has been shown to form stable complexes with metals such as copper, zinc, and nickel. These complexes are used in various fields, including catalysis, materials science, and environmental applications. The sulfur atom's ability to donate electron density to metal ions makes it a valuable ligand in the design of catalysts for organic reactions, particularly in reactions that require metal centers to activate molecules. The complexes of 2-mercaptopyridine have also been explored for their ability to catalyze reactions such as oxidation, reduction, and polymerization.

Another significant application of 2-mercaptopyridine is in medicinal chemistry. The compound exhibits antioxidant properties, which makes it a potential candidate for treating diseases associated with oxidative stress, such as neurodegenerative diseases, cardiovascular diseases, and cancer. The thiol group in 2-mercaptopyridine is known to interact with free radicals, preventing cellular damage and offering potential therapeutic benefits. Moreover, its ability to bind to metals, such as iron and copper, has led to its investigation in the treatment of metal-related disorders, such as Wilson's disease and Alzheimer's disease, where metal ion accumulation in tissues can lead to pathological conditions.

In addition to its antioxidant and metal-chelating properties, 2-mercaptopyridine has also been studied for its potential antibacterial and antifungal activities. It is believed that the thiol group interacts with the metal centers in the enzymes of microbial organisms, disrupting their normal function and inhibiting their growth. These properties have made 2-mercaptopyridine an interesting compound for further research in the development of new antimicrobial agents, particularly in the face of increasing antibiotic resistance.

Furthermore, 2-mercaptopyridine has applications in the field of corrosion inhibition. It has been shown to interact with metal surfaces, forming protective layers that prevent corrosion, especially in environments where metals are exposed to harsh chemicals or moisture. This property has led to its use in industries such as the oil and gas industry, where equipment and infrastructure are at risk of corrosion due to exposure to corrosive elements.

In conclusion, 2-mercaptopyridine is a versatile and reactive compound with a range of applications in materials science, medicinal chemistry, and industrial processes. Its ability to form metal complexes, act as an antioxidant, and provide corrosion resistance has made it an important substance in various research and industrial settings. Further studies into its biological activities and potential therapeutic applications may reveal even more uses for this interesting chemical substance.

References

2023. Comparison of Anti-Trop2 Extracellular Domain Antibodies. Applied Biochemistry and Biotechnology, 195(12).
DOI: 10.1007/s12010-023-04706-4

2023. Sulfur-bridging the gap: investigating the electrochemistry of novel copper chelating agents. JBIC Journal of Biological Inorganic Chemistry, 28(7).
DOI: 10.1007/s00775-023-02013-1

2023. Thermodynamic and structural investigation of the interaction of quaternized 2,3-octakis-[(2-mercaptopyridine)phthalocyaninato] copper. Journal of Molecular Recognition, 36(11).
DOI: 10.1002/jmr.3072