I. B. Chernikova, S. Khursan, L. Spirikhin
Jul 29, 2015
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Influential Citations
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Journal
Chemistry of Heterocyclic Compounds
Abstract
5-Bromo-5-fluoro- and 5-chloro-5-fluoro-6-hydroxy-5,6-dihydrouracils were obtained in high yields by oxidative halogenation of 5-fluorouracil. Nitration of 5-fluorouracil gave 5-fluoro-6-hydroxy-5-nitro-5,6-dihydrouracil. Theoretical calculations in B3LYP/6-311+G(d,p) // B3LYP/6-311G(d,p) + IEFPCM approximation and GIAO simulation of 13C NMR spectra and spin-spin coupling constants agree with the structure of the compounds obtained, which manifest an equatorial orientation of the fluorine atom and an axial orientation of the hydroxy group at position 6 of the dihydrouracil ring. The principal possibility of oxidative iodination of 5-halouracils was studied in B3LYP/CEP-121G approximation. It was found that reversible elimination of iodine by a nucleophilic agent to give the original compounds is the main transformation pathway of the intermediate in this process.