PTSA catalyzed simple and green synthesis of benzothiazole derivatives in water

An efficient synthesis of 2-arylbenzothiazoles using silica sulfuric acid, oxalic acid and aluminum chloride hydrate as heterogeneous and homogeneous catalyst systems

“…As previously suggested [37][38][39][40][41][42][43][44][45][46][47][48][49][50] , the reaction may proceed through the formation of imine I from aldehydes and 2-aminothiophenol. Subsequent cyclization to 2,3-dihydrobenzothiazole II followed by oxidation in air would afford 2-arylbenzothiazoles (Scheme 2).…”

Synthesis of novel bis‐ and poly(benzimidazoles) as well as bis‐ and poly(benzothiazoles) as anticancer agents

“…The significant importance of benzimidazoles and benzothiazoles and their applications in diverse areas prompted us to study new routes for their synthesis and to construct new structures of their derivatives. Our first trial to synthesize the target 1,4‐bis(4‐(1 H ‐benzo[ d ]imidazol‐2‐yl)phenoxy)butane 5a and 1,4‐bis(4‐(benzo[ d ]thiazol‐2‐yl)phenoxy)butane 6a included the reaction of the appropriate 4‐(1 H ‐benzo[ d ]imidazol‐2‐yl)phenol 4 (X = NH) and 4‐(benzo[ d ]thiazol‐2‐yl)phenol 4 (X = S), respectively, with 1,4‐dibromoethane in basic solutions (Route A, Scheme ). Using this strategy, compound 6a could be obtained but in low yield.…”

Nanosized Mn(acac)3 Anchored on Amino Functionalized Silica for the Selective Oxidative Synthesis of 2-arylbenzimidazoles, 2-arylbenzothiazoles and Aerobic Oxidation of Benzoins in Water

“…For example, Yang et al [76] have reported the synthesis of 2-arylbenzothiazoles at 100°C using CTAB; Azizi et al [77] used PTSA at 100°C; Chakraborti et al [46] carried out the reaction without using any catalyst at 110°C. Very few catalytic systems have been reported for the synthesis of 2-arylbenzimidazoles in water.…”