2-Mercaptobenzimidazole
[CAS# 583-39-1]

Identification

• Classification: API >> Synthetic anti-infective drugs >> Anti-tuberculosis leprosy
• Name: 2-Mercaptobenzimidazole
• Synonyms: 2-Benzimidazolethiol; Benzimidazole-2-thiol
• Molecular Formula: C₇H₆N₂S
• Molecular Weight: 150.20
• CAS Registry Number: 583-39-1
• EC Number: 209-502-6
• SMILES: C1=CC=C2C(=C1)NC(=S)N2

Properties

• Solubility: <0.1 g/100 mL at 23.5 ºC (water), soluble (alcohol) (Expl.)
• Density: 1.4±0.1 g/cm³, Calc.^*, 1.42 g/mL (Expl.)
• Melting point: 300-304 ºC (Expl.)
• Index of Refraction: 1.771, Calc.^*
• Boiling Point: 332.1±25.0 ºC (760 mmHg), Calc.^*
• Flash Point: 154.7±23.2 ºC, Calc.^*

Safety Data

• Hazard Symbols: GHS06;GHS07;GHS08 Danger
• Hazard Statements: H301-H302-H311-H312-H315-H317-H319-H332-H335-H372-H373-H413
• Precautionary Statements: P260-P261-P262-P264-P264+P265-P270-P271-P272-P273-P280-P301+P316-P301+P317-P302+P352-P304+P340-P305+P351+P338-P316-P317-P319-P321-P330-P332+P317-P333+P317-P337+P317-P361+P364-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	3	H301
Eye irritation	Eye Irrit.	2	H319
Skin sensitization	Skin Sens.	1	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - repeated exposure	STOT RE	1	H372
Acute toxicity	Acute Tox.	4	H332
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	4	H312
Specific target organ toxicity - single exposure	STOT SE	3	H335
Specific target organ toxicity - single exposure	STOT SE	1	H370
Reproductive toxicity	Repr.	2	H361
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Reproductive toxicity	Repr.	1B	H360

Discovory and Applicatios

2-Mercaptobenzimidazole is an organic compound that features both a benzene ring and a benzimidazole structure, with a thiol group (-SH) attached to the carbon adjacent to the nitrogen of the imidazole ring. It is widely recognized for its versatility in various chemical processes and its applications in several industrial and pharmaceutical domains.

The discovery of 2-Mercaptobenzimidazole can be traced back to the exploration of sulfur-containing heterocyclic compounds, where the potential of thiol groups in enhancing chemical reactivity and providing unique functional properties was well understood. Benzimidazole derivatives themselves were first synthesized in the early 20th century, and the incorporation of the thiol group was found to significantly enhance their ability to interact with metals and other molecules, opening up new pathways for their use in several key applications.

One of the primary uses of 2-Mercaptobenzimidazole is in the field of metal chelation. The thiol group in the compound is highly reactive, making it effective at forming complexes with metal ions. This ability is particularly valuable in applications like corrosion inhibition, where the compound can prevent the degradation of metals by forming protective coatings. It has been employed in various industries to protect metal surfaces from rust and oxidation, particularly in environments where exposure to moisture and air is a concern, such as in the automotive, construction, and aerospace sectors.

Another important application of 2-Mercaptobenzimidazole is in the field of medicine, where it has been studied for its potential as an antimicrobial agent. Research has shown that the compound possesses strong antibacterial and antifungal properties, making it an effective candidate for the development of treatments for various infectious diseases. The compound has been particularly noted for its ability to inhibit the growth of both Gram-positive and Gram-negative bacteria, which are often resistant to other forms of treatment. This antimicrobial activity is attributed to the thiol group, which can disrupt the function of microbial enzymes and interfere with the structure of microbial cell membranes.

2-Mercaptobenzimidazole has also gained attention in the field of polymer chemistry, where it is utilized as a vulcanizing agent in rubber production. Its ability to crosslink polymer chains enhances the strength and durability of rubber, making it suitable for use in products that require resistance to heat, chemicals, and wear. In this application, the compound helps to improve the performance and longevity of rubber materials used in tires, gaskets, and seals, among other products.

In addition to these applications, 2-Mercaptobenzimidazole is employed in the synthesis of various other chemicals. Its reactive thiol group allows it to participate in a variety of organic reactions, including the formation of disulfide bonds and the development of sulfur-containing polymers. These reactions expand its utility in producing specialty chemicals and materials with specific functional properties, such as in the production of certain adhesives and coatings.

Overall, the discovery and diverse applications of 2-Mercaptobenzimidazole underscore its importance in a wide range of industries, from metal protection and medicine to polymer chemistry and beyond. Its unique structure and reactivity continue to make it a valuable compound for scientists and engineers seeking innovative solutions to complex challenges.

References

2024. In vitro and in vivo anti-pigmentation effects of 2-mercaptobenzimidazoles as nanomolar tyrosinase inhibitors on mammalian cells and zebrafish embryos: Preparation of pigment-free zebrafish embryos. European Journal of Medicinal Chemistry.
DOI: 10.1016/j.ejmech.2024.116136

2024. Molecular modeling applied to corrosion inhibition: a critical review. npj Materials Degradation.
DOI: 10.1038/s41529-024-00478-2

2024. Recent advancements in silica filled natural rubber composite: A green approach to achieve smart properties in tyre. Journal of Polymer Research.
DOI: 10.1007/s10965-024-03956-y