Anisotropic and hydrogen bonding effects in phenylglyoxamides and mandelamides: theoretical and NMR conformational evaluation

Magn Reson Chem. 2008 May;46(5):418-26. doi: 10.1002/mrc.2192.

Abstract

Interesting anisotropic effects were observed for phenylglyoxamides and their respective mandelamides. Such effects were observed in experimental (1)H and (13)C NMR (in CDCl(3), CD(3)OD, and DMSO-d(6) solvents) and in some cases with good correlation to theoretical (1)H and (13)C NMR DFT-GIAO (B3LYP/6-311++G**//B3LYP/6-31G*) calculations. A systematic conformational analysis of these compounds was performed in a two-step methodology, using PM3 and DFT (B3LYP/6-31G*) calculations; with good accomplishment and computational time economy. It was observed that intramolecular hydrogen bonding plays a significant role in the conformation of such compounds. Finally, a geminal nonequivalence of an N-CH(2) moiety, in one of the alkyl side chain (R1 = R2), was found for the tertiary mandelamides studied.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anisotropy
  • Computer Simulation
  • Hydrogen / chemistry*
  • Hydrogen Bonding
  • Magnetic Resonance Spectroscopy / methods*
  • Mandelic Acids / chemistry*
  • Models, Chemical*
  • Models, Molecular*
  • Molecular Conformation
  • Sulfonylurea Compounds / chemistry*

Substances

  • Mandelic Acids
  • Sulfonylurea Compounds
  • glyoxamide
  • mandelamide
  • Hydrogen