5-FLUORO-5-HALO- AND 5-FLUORO-5-NITRO-SUBSTITUTED URACIL DERIVATIVES. SYNTHESIS AND STRUCTURE

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.

How to Cite
Chernikova, I. B.; Khursan, S. L.; Spirikhin, L. V.; Yunusov, M. S. Chem. Heterocycl. Compd. 2015, 51, 568. [Khim. Geterotsikl. Soedin. 2015, 51, 568.]

For this article in the English edition see DOI 10.1007/s10593-015-1737-y