title: Synthesis of a new series of N,N'-dimethyltetrahydrosalen (H2[H2Me]salen) ligands by the reductive ring-opening of 3,3'-ethylene-bis(3,4-dihydro-6-substituted-2H-1,3-benzoxazines).
abstract: A new series of N,N'-bis(2'-hydroxy-5'-substituted-benzyl)-N,N -dimethylethane-1,2-diamines (N,N'-dimethyltetrahydrosalen) ligands were prepared in good yield by reduction of the respective 3,3'-ethylene-bis(3,4-dihydro-6-substituted-2H-1,3-benzoxazine) precursors with sodium borohydride . The ligands were characterized by IR, NMR, and elemental analysis, which showed the compounds to be consistent with the proposed structures. Ring-opening reactions of bis-1,3-benzoxazines in the presence of sodium borohydride to produce N,N'-dimethylated tetrahydrosalens (H(2) [H(2)Me]salen) have not been reported in the literature.
authors.affiliation: Departamento de Química, Universidad Nacional de Colombia, Bogotá, Colombia, A.A. 14490, Colombia. ariverau@unal.edu.co
authors.forename: Augusto
authors.initials: A
authors.lastname: Rivera
authors.forename: Jicli José
authors.initials: JJ
authors.lastname: Rojas
authors.forename: Jairo
authors.initials: J
authors.lastname: Salazar-Barrios
authors.forename: Mauricio
authors.initials: M
authors.lastname: Maldonado
authors.forename: Jaime
authors.initials: J
authors.lastname: Ríos-Motta
mesh_terms: D048588:Benzoxazines / Q000737:chemistry*; D005029:Ethylenediamines / Q000138:chemical synthesis* / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D048588:Benzoxazines; D005029:Ethylenediamines; D008024:Ligands; C011452:disalicylaldehyde ethylenediamine