Acid-base properties and keto-enol equilibrium of a 5-substituted derivative of 1,3-diethyl-2-thiobarbituric acid
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DOI:
10.1515/hc-2016-0011URI (для ссылок/цитирований):
https://elib.sfu-kras.ru/handle/2311/32960Дата:
2016-04Журнал:
Heterocyclic CommunicationsКвартиль журнала в Scopus:
Q4Квартиль журнала в Web of Science:
Q4Библиографическое описание:
Lutoshkin, M. A. Acid-base properties and keto-enol equilibrium of a 5-substituted derivative of 1,3-diethyl-2-thiobarbituric acid [Текст] / M. A. Lutoshkin, N. N. Golovnev // Heterocyclic Communications. — 2016. — Т. 22 (№ 2). — С. 111-116Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.
Аннотация:
This article deals with spectrophotometric and ab initio studies of 1,3-diethyl-7-hydroxy-5,5,7-trimethyl-2-thioxo-1,2,3,5,6,7-hexahydro-4Hpyrano[2,3-d]pyrimidin-4-one (HDEAC). Acid-base properties for I = 0.25 and in a strongly acidic solution of HCl (I -> 0) were investigated. The obtained value of pK(a) (5.79 +/- 0.02) and -pK(H) (1.68 +/- 0.03) show that this compound is a weaker acid than thiobarbituric acid. For interpretation of the spectrophotometric data the ab initio methods with density functional theory at level PBE0/cc-pVDZ/SMD were used. The most energetically favorable structures for neutral and cationic forms of HDEAC were proposed.