Water-Promoted Chlorination of 2-Mercaptobenzothiazoles was written by Wimmer, Laurin;Parmentier, Michael;Riss, Bernard;Kapferer, Tobias;Ye, Chao;Li, Lei;Kim, Hongyong;Li, Jialiang. And the article was included in Synthesis in 2018.Synthetic Route of C7H3BrClNS This article mentions the following:
The substituted 2-mercaptobenzothiazoles were prepared (by reaction of 2-haloanilines and potassium o-Et carbonodithioate) and underwent chlorination using sulfuryl chloride/water so as to yield 2-chlorobenzothiazoles such as I [X = C, N; R = H, 6-Me, 7-Cl, etc.]. This straightforward and widely used reaction was impeded due to the poor reproducibility and low reaction yields. In this protocol, it was reported that the simple addition of water to the reaction lead to remarkable improvements in reaction efficiency because of the formation of acid through partial hydrolysis of sulfuryl chloride. The observations of improved yields were also obtained in the presence of some anhydrous acidic additives, but the simple combination of sulfuryl chloride and water reproducibly provided excellent yields for a range of chlorinated products I. In the experiment, the researchers used many compounds, for example, 6-Bromo-2-chlorobenzothiazole (cas: 80945-86-4Synthetic Route of C7H3BrClNS).
6-Bromo-2-chlorobenzothiazole (cas: 80945-86-4) belongs to thiazole derivatives. The thiazole ring has been identified as a central feature of numerous natural products, perhaps the most famous example of which is epothilone. The nitrogen in thiazole is sp2 hybridized and the lone pair of electrons localized on the nitrogen is less reactive due to increased aromatic character and decreased basicity. It is protonated and alkylated/acylated at nitrogen forming hydrochloride and quaternary thiazolium salt.Synthetic Route of C7H3BrClNS
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica