Synthesis of 2‐Arylbenzothiazoles by Copper‐Catalyzed One‐Pot Three‐Component Reactions in Water

Abstract

Copper‐catalyzed three‐component reactions of 2‐iodoanilines, benzylamines, and sulfur powder are reported to afford benzothiazoles in a simple one‐pot procedure by using water as solvent. A variety of 2‐arylbenzothiazoles were obtained in moderate to good yields up to 88%.

Recent Advances in the Synthesis of Heterocycles via Reactions Involving Elemental Sulfur

“…Sulfur could be used as a sulfide source in the reaction with an o-iodoaniline 212 to provide the coresponding 2-aminothiophenol, which could further involve in an oxidative condensation reaction with a suitable C-2 precursor 213 and result in 2-substituted benzothiazoles 214 (Scheme 70). [75][76][77][78][79][80][81][82] Benzaldehydes (entries 1-2), benzylamines (entries 3-4), dibenzyl disulfides (entry 5), phenylacetic acids (entry 6), benzyl chlorides (entry 7) could be used as C-2 precursor. Phase transfer agents such as tetrasubstituted ammonium salts could also be used for this purpose.…”

Selective Synthesis of Imines by Photo-Oxidative Amine Cross-Condensation Catalyzed by PCN-222(Pd)

“…The antitumor agent 2-(3,4-dimethoxyphenyl)-5-fluorobenzothiazole, also known as PMX 610, presents a benzothiazole scaffold that could be obtained via condensation of the corresponding 2-aminothiol and 3,4-dimethoxybenzylamine (Scheme ). This pathway offers a new alternative to existing methods, which require temperatures over 140 °C or less-stable starting materials. − …”