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Deuterium exchange of 4‐pyrimidones and 4‐pyrimidthiones
Author(s) -
Wright George E.,
Bauer Ludwig,
Bell Charles L.
Publication year - 1966
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570030409
Subject(s) - chemistry , deuterium , catalysis , triethylamine , hydrogen–deuterium exchange , iodide , base (topology) , oxide , hydrogen , inorganic chemistry , alkyl , medicinal chemistry , organic chemistry , mathematical analysis , physics , mathematics , quantum mechanics
The hydrogen‐deuterium exchange of H‐2 in 4‐pyrimidone, a number of 1‐ and 3‐alkyl‐4‐pyrimidones and several of their thione analogs in deuterium oxide at moderate temperatures is reported. This reaction is apparently not susceptible to acid or base catalysis. Cations of the 4‐pyrimidones were found not to exchange H‐2 at all in acid media. Catalytic amounts of bases do not alter the exchange rates whereas more concentrated alkali decompose the pyrimidone. However, 1,4(3,4)‐dihydro‐1,3‐dimethyl‐4‐oxopyrimidinium iodide (and its 6‐methyl analog) exchange H‐2 quite rapidly in neutral deuterium oxide, almost instantly when triethylamine is added as a catalyst, and very slowly in dilute solutions of deuterium chloride in deuterium oxide. Mechanisms are proposed to account for these phenomena.