2-Mercaptobenzothiazole
[CAS# 149-30-4]

Identification

• Classification: Chemical pesticide >> Herbicide >> Amide herbicide
• Name: 2-Mercaptobenzothiazole
• Synonyms: 2-Benzothiazolethiol; Benzothiazole-2-thiol
• Molecular Formula: C₇H₅NS₂
• Molecular Weight: 167.24
• CAS Registry Number: 149-30-4
• EC Number: 205-736-8
• SMILES: C1=CC=C2C(=C1)NC(=S)S2

Properties

• Density: 1.4±0.1 g/cm³, Calc.^*, 1.42 g/mL
• Melting point: 172-180 °C
• Index of Refraction: 1.757, Calc.^*
• Boiling Point: 281.3±23.0 °C (760 mmHg), Calc.^*
• Flash Point: 123.9±22.6 °C, Calc.^*, 243 °C (dec.)
• Water solubility: <0.1 g/100 mL at 19 °C

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

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Risk Statements: H317-H400-H410
• Safety Statements: P261-P272-P273-P280-P302+P352-P321-P333+P317-P362+P364-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin sensitization	Skin Sens.	1	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Carcinogenicity	Carc.	1B	H350

• Transport Information: UN 3077

Discovery and Applications

2-Mercaptobenzothiazole (MBT) is an organic compound with the molecular formula C7H6N2S2. It features a benzothiazole ring with a mercapto (-SH) group attached at the second position. This compound has a long history of usage, dating back to its synthesis in the early 20th century. The initial discovery of 2-mercaptobenzothiazole is attributed to the growing interest in thiazole derivatives, which are known for their diverse chemical properties and biological activities.

The synthesis of 2-mercaptobenzothiazole can be achieved through several methods, including the reaction of 2-aminobenzenethiol with carbon disulfide in the presence of an appropriate base. The resulting product has become an important intermediate in the production of various chemicals and materials due to its unique chemical structure. The presence of both sulfur and nitrogen atoms in the benzothiazole ring contributes to its reactivity, making it a valuable compound in multiple applications.

One of the primary applications of 2-mercaptobenzothiazole is in the rubber industry, where it is used as a vulcanization accelerator. The compound enhances the cross-linking process of rubber, leading to improved elasticity, strength, and durability of rubber products. This property has made MBT a crucial component in the production of tires, footwear, and other rubber goods, where performance and longevity are paramount. The efficiency of MBT as a vulcanization accelerator has led to its widespread adoption in various rubber formulations, contributing to the development of high-quality rubber materials.

In addition to its role in rubber manufacturing, 2-mercaptobenzothiazole has found applications in the field of agriculture as a fungicide and herbicide. The compound exhibits antifungal properties, making it effective against a variety of plant pathogens. Its use in agricultural formulations helps to protect crops from diseases, ensuring higher yields and better quality produce. Research has shown that MBT can inhibit the growth of fungi, thus providing a viable option for sustainable agricultural practices.

Moreover, 2-mercaptobenzothiazole is also utilized in the field of analytical chemistry. It is employed as a reagent for the detection of heavy metals, particularly in the analysis of water and soil samples. The ability of MBT to form complexes with metal ions enables its application in environmental monitoring, aiding in the assessment of pollution levels and the safety of water sources.

Despite its beneficial applications, the use of 2-mercaptobenzothiazole raises certain safety and environmental concerns. The compound is known to be toxic to aquatic organisms, necessitating caution in its handling and disposal. Regulatory guidelines are in place to mitigate risks associated with its use, emphasizing the importance of following safety protocols in industrial settings.

In summary, 2-mercaptobenzothiazole is a versatile compound with significant applications in the rubber industry, agriculture, and analytical chemistry. Its discovery and development highlight the importance of thiazole derivatives in chemical synthesis and material science. As research continues to explore its properties and potential applications, 2-mercaptobenzothiazole may contribute to advancements in sustainable practices and innovative solutions across various industries.

References

2010. Soybean Peroxidase-Catalyzed Removal of an Aromatic Thiol, 2-Mercaptobenzothiazole, from Water. Water Environment Research, 82(11).
DOI: 10.2175/106143010x12681059116617

2020. 2-Mercaptobenzothiazole in urine of children and adolescents in Germany - Human biomonitoring results of the German Environmental Survey 2017 (2014-2017). International Journal of Hygiene and Environmental Health, 228.
DOI: 10.1016/j.ijheh.2020.113540

2021. Discovery of selective fragment-sized immunoproteasome inhibitors. European Journal of Medicinal Chemistry, 219.
DOI: 10.1016/j.ejmech.2021.113455