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).
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.
Rivera
Augusto
A
Departamento de Química, Universidad Nacional de Colombia, Bogotá, Colombia, A.A. 14490, Colombia. ariverau@unal.edu.co
Rojas
Jicli José
JJ
Salazar-Barrios
Jairo
J
Maldonado
Mauricio
M
Ríos-Motta
Jaime
J
D048588:Benzoxazines / Q000737:chemistry*; D005029:Ethylenediamines / Q000138:chemical synthesis* / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure
D048588:Benzoxazines; D005029:Ethylenediamines; D008024:Ligands; C011452:disalicylaldehyde ethylenediamine