5-Pyrimidinols: Novel Chain-Breaking Antioxidants More Effective than Phenols was written by Pratt, Derek A.;DiLabio, Gino A.;Brigati, Giovanni;Pedulli, Gian Franco;Valgimigli, Luca. And the article was included in Journal of the American Chemical Society in 2001.Reference of 51834-97-0 This article mentions the following:
On transition from phenol → 3-pyridinol → 5-pyrimidinol the IP increased by 24.3 kcal/mol, but the O-H BDE by only 2.5 kcal/mol (substituent effects were conserved in the 3 series), suggesting that 5-pyrimidinols should be effective H-atom donors that are more stable to air oxidation than similarly substituted phenols. Thus, 2-(dimethylamino)-4,6-dimethyl-5-pyrimidinol was prepared and exhibited a lower O-H BDE and higher IP than α-tocopherol. The 5-pyrimidinols reacted substantially faster with alkyl radicals than the corresponding phenols, and in the reaction with peroxyl radicals the two 5-pyrimidinols evaluated reacted at the same and 1/3 the rate of the corresponding phenol. In the experiment, the researchers used many compounds, for example, 5-Hydroxy-2-methoxylpyridine (cas: 51834-97-0Reference of 51834-97-0).
5-Hydroxy-2-methoxylpyridine (cas: 51834-97-0) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase and 140.4 kJ·mol−1 in the gas phase. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Reference of 51834-97-0