ChemInform Abstract: Nucleosides. Part 3. Synthesis of Novel 1,3,4‐Oxadiazole Nucleosides.

Abstract

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Nucleosides 8 [18]: Ribosylation of Fused Quinazolines—Synthesis of New [1,2,4]Triazolo[5,1‐b]‐ and [1,2,4]Triazino[3,2‐b]quinazoline Nucleosides of Fluorescence Interest

“…Their IR spectra revealed three characteristic bands for (C=O)-stretching bands of product 16 and four bands for product 20 (see Section 2). The 1 H NMR spectra in CDCl 3 of 16 and 20 showed as in the case of that of compounds 7-10 signals at 6.10-6.15 assigned to the anomeric proton of the ribose moiety with a spin-spin coupling constant equal to 7.5 Hz ( -configuration [18][19][20][21][22][23][24]). 13 C NMR Spectrum in CDCl 3 of 16 as an example revealed signals at 29,50,59,71,78,84,93,121,[125][126][127][128][129][130][131][132][133][134][135][136][137][138][139][140]151,159,164,168 (CO).…”

“…The structures of the latter products 7-10, 16, and 20 were established and confirmed on the bases of their elemental analyses and spectral data. Thus, their 1 H NMR spectra in CDCl 3 showed a doublet signal at 6.10-6.15 assigned to the anomeric proton of the ribose moiety with a spin-spin coupling constant equal to 7.5 Hz, which corresponds to a diaxial orientation for the 1 -and 2 -H protons; that is, the -configuration (high 1 ,2 ) [18][19][20][21][22][23][24]. 13 The structure of nucleoside 10 may exist in two forms, thiol form (10A) and thione form (10B or 10C) (Scheme 2).…”

“…In the view of our observations of the aforementioned biological and fluorescence [1-4, 15, 17] importance of quinazoline derivatives and as part of our continuing interest in the synthesis of new nucleosides [18][19][20][21][22][23][24] as expected as new fluorescent molecules, it has encouraged us to study a synthetic strategy of new derivatives of [1,2,4]triazolo [5,1-b]-and [1,2,4]triazino [3,2-b]quinazoline nucleosides of fluorescence 2 Journal of Chemistry interest, which have not been yet reported in the literature. Our final goal will be directed to find new nucleosides as expected to be fluorescent and to study their biological activity in further investigations.…”