NMR investigation of methyl-2,4-dimethoxysalicylate: Effect of solvent and temperature

1H NMR and 13C NMR of methyl-2,4-dimethoxysalicylate 2 was measured in chloroform-d at the temperature range of 220-330 K, in dimethyl sulfoxide-d6 at the temperature range of 300-400 K and in a polar protic solvent (CD3OD) at 300 K. The structure of 2 in liquid phase (solvent) is compared with those in solid phase (X-ray) and in the gas phase (quantum mechanical calculations). The relationship between molecular geometry, 1H NMR chemical shift and W coupling of involved protons has a complex nature, but hydrogen bonds [CO⋯H-O and CO⋯H-CH2O] strength is the principle factor.