Application
2-Mercaptobenzoxazole is a widely used organic scaffold in medicinal chemistry.
2-Mercaptobenzoxazole and their derivatives are known to posses several biological activities such as antibacterial, antifungal, antiinflammatory, insecticidal and herbicidal. 4-0xo-thiazolidines have also played an important activities as analgesic, anti-HIV, antitubercular, anthelmentic, dye-stuffs, fluorescent and as a photosensitizer. The incorporation of 4-oxothiazolidine and their 5-arylidene moieties in 2-mercaptobenzoxazole frame work has been found to enhance the activity.
Synthesis
1. 15 mL of ethanol, 3 mL of water, 10 mmol of o-aminophenol, 10 mmol of carbon disulfide, and 10 mmol of potassium hydroxide were sequentially added to the reaction flask.
2. The reaction mixture was heated to 80 °C and stirred at reflux for 3 hours at this temperature.
3. Upon completion of the reaction, a small amount of zeolite was added to the mixture and filtered while hot.
4. Warm the filtrate to 70 °C and slowly pour it into a beaker containing 10 mL of warm water (preheated to 60-70 °C).
5. cool the beaker in an ice-water bath to induce precipitation of the product.
6. The precipitated white transparent needle-like crystals were collected by filtration and dried to give 1.23 g of 2-mercaptobenzoxazole in 81% yield.
References
[1] Patent: CN108794421, 2018, A. Location in patent: Paragraph 0024; 0025; 0027
[2] Heteroatom Chemistry, 2001, vol. 12, # 3, p. 151 - 155
[3] Letters in Organic Chemistry, 2010, vol. 7, # 7, p. 519 - 527
[4] Bioorganic and Medicinal Chemistry, 2016, vol. 24, # 21, p. 5374 - 5379
[5] Journal of Medicinal Chemistry, 1994, vol. 37, # 7, p. 913 - 923
