Talk:2-Pyridone
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[edit] 2-Pyridone favored in water
" Nonpolar solvents favour the 2-Pyridone whereas in polar solvents like alcohols and water the 2-Hydroxypyridone is favoured. "
I believe this is backwards, plus the spelling error in 2-Hydroxypyridone, so I'm changing it. It's 2-hydroxypyridine in gas phase, and the more polar the solvent, the more stable the 2-pyridone. The explanation for this is stabilization of charge separation in high dielectric environments. 2-pyridone has greater charge separation, as can be seen by considering its mesionic aromatic resonance contributor. There's a discussion of the solvent effects and a large table of pKts for substituted 2-pyridones in J Elguero, C Marzin, AR Katritzky, P Linda, The Tautomerism of Heterocycles, Advances in Heterocyclic Chemistry, Supplement 1 (1976).
[edit] High boiling point?
The boiling point of 300+ degrees centrigrade is much higher than reported elsewhere in (internet) publications. But most refer to the hydroxypyridine tautomer, so I'm not sure. Could anyone confirm? Wim van Dorst 20:56, 30 January 2006 (UTC).
- There are several boiling points mentioned in literature. I will give literature link when I will have next possibility to use Beilstein-Crossfire!Stone 07:13, 31 January 2006 (UTC)
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- Me culpa mea macima culpa! The boiling point is cited in literature but in reality decomposition takes place at 280°C which is cited in other literature.Stone 19:13, 11 February 2006 (UTC)
[edit] High pKa? or low pKa?
In Kirk-Othmer (4th) under Pyridines, I see that the pKa for 2-pyridone is 1.25. That's quite some difference from the 11+ as currently listed in the table. Or is this a mix up of various tautomers? Wim van Dorst 21:11, 30 January 2006 (UTC).
- Bordwell lists 2-pyridone as 17.0 in DMSO. However, in water it has two pKas: 0.75 and 11.62. ~K 04:29, 31 January 2006 (UTC)
[edit] New literature
Transition States for Glucopyranose Interconversion Brett E. Lewis, Nankishoresing Choytun, Vern L. Schramm, and Andrew J. Bennet J. Am. Chem. Soc.; 2006; 128(15) pp 5049 - 5058; (Article) DOI: 10.1021/ja0573054 ADALSTEINSSON H, BRUICE TC JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 120 (14): 3440-3447 APR 15 1998
