Metal-free and green synthesis of a series of new bis(2-alkylsulfanyl-[1, 3, 4]thiadiazolyl)-5, 5′-disulfides and 2, 2′-Dibenzothiazyl disulfide via oxidative self-coupling using hydrogen peroxide. (1st February 2022)

• Record Type: Journal Article
• Authors: Ling Ong, Chiu; Heidelberg, Thorsten; Ching Juan, Joon; Ghaffari Khaligh, Nader
• Is Part Of: Polyhedron. Volume 213(2022)
• Publication Date: 2022-02-01
• Subjects: Thiadiazolyl-5, 5'-disulfides -- 2, 2'-dibenzothiazyl disulfide -- Oxidative coupling -- Metal-free -- Green synthesis; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2021.115610
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: A series of new bis(2-alkylsulfanyl-[1, 3, 4] thiadiazolyl)-5, 5′-disulfide derivatives containing two 1, 3, 4-thiadiazole rings linked by SS bond spacer were synthesized via the oxidative self-coupling of 5-alkylsulfanyl-[1, 3, 4] thiadiazole-2-thiol using hydrogen peroxide and ethanol. Abstract: Many disulfide and 1, 3, 4-thiadiazole-1, 2-dithiol compounds have been extensively investigated in the pharmaceutical industry due to their unique biological properties. A series of new bis(2-alkylsulfanyl-[1, 3, 4]thiadiazolyl)-5, 5′-disulfide derivatives containing two 1, 3, 4-thiadiazole rings linked by SS bond spacer were synthesized via the oxidative self-coupling of 5-alkylsulfanyl-[1, 3, 4]thiadiazole-2-thiol using hydrogen peroxide and ethanol as green oxidant and solvent, respectively. The excellent yields of 93–97% with 100% conversion were achieved with a simple one-pot synthesis. There is no over-oxidation of 5-alkylsulfanyl-[1, 3, 4]thiadiazole-2-thiol and 2-mercaptobenzothiadiazole that leads to the formation of by-products such as thiosulfinate, thiosulfonate, and sulfonic acid. In this process, a straightforward, short reaction time, metal-free, reusable solvent, and mild reaction conditions are applied to produce bis(2-alkylsulfanyl-[1, 3, 4]thiadiazolyl)-5, 5′-disulfides and 2, 2′-dibenzothiazyl disulfide. Therefore, the oxidative self-coupling is potential for other disulfide compounds.