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)

Molecules. 2010 Jun 7;15(6):4102-10. doi: 10.3390/molecules15064102.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzoxazines / chemistry*
  • Ethylenediamines / chemical synthesis*
  • Ethylenediamines / chemistry*
  • Ligands
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Structure

Substances

  • Benzoxazines
  • Ethylenediamines
  • Ligands
  • disalicylaldehyde ethylenediamine