Synthesis of 1-(2-bromo-1-arylethyl)-1H-benzotriazoles via NBS promoted addition of 1H-benzotriazole to alkene: Relevance in benzotriazole ring cleavage. Issue 14 (3rd April 2020)

• Record Type: Journal Article
• Authors: Singh, Mala; Bose, Priyanka; Singh, Anoop S.; Tiwari, Vinod K.
• Is Part Of: Tetrahedron. Volume 76:Issue 14(2020)
• Publication Date: 2020-04-03
• Subjects: N-acyl benzotriazole -- 1H-benzotriazole -- Benzotriazole ring cleavage (BtRC) -- N-bromosuccinimide -- E2-ellimination -- Ring opening; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2020.131078
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: A cost-effective and expeditious one-pot synthesis of 1-(2-bromo-1-arylethyl)-1 H -benzotriazoles has been devised by reacting styrene and their derivatives with 1 H -benzotriazole in presence of N -bromosuccinimide in anhydrous CH2 Cl2 at room temperature. Further, the resulted compounds undergo E2 -ellimination to afford the respective 1-(1-aryl-vinyl)-1 H -benzotriazoles. At the end, 1-(1-phenylvinyl)-1 H -benzotriazoles underwent benzotriazole ring cleavage (BtRC) under free radical condition to produce phenanthridine as the final product. Graphical abstract: Image 1 Highlights: A novel and expeditious one-pot synthesis of 1-(2-bromo-1-arylethyl)-1 H -benzotriazoles has been devised by reacting styrene with 1 H -benzotriazole in presence of NBS in anhydrous CH2 Cl2 at room temperature. The resulted compounds undergo E2 -ellimination to afford respective 1-(1-phenylvinyl)-1 H -benzotriazoles. 1-(1-Phenylvinyl)-1 H -benzotriazole underwent benzotriazole ring cleavage (BtRC) under free radical condition to produce phenanthridine.