Synthesis and 15N- and 17O-NMR spectra of 5-methyl(15N2)[O2,O4-17O2]uridine (=(15N2)[O2,O4-17O2]ribosylthymine)

Article abstract of DOI:10.1002/hlca.19950780507

The 5-methyl(¹⁵N₂)[O²,O⁴-¹⁷O₂]uridine (=(¹⁵N₂)[O²,O⁴-¹⁷O₂]ribosylthymine; 15) was synthesized and analyzed by ¹⁵N- and ¹⁷O-NMR spectroscopy. (¹⁵N₂)Urea was condensed with 2,3-dibromo-2-methylpropanoyl chloride (3) and cyclized to form (¹⁵N₂)thymine (5). After glycosidation, the ¹⁷O isotopes were introduced in two separate steps: hydrolytic ring opening of 2,5'-anhydro derivative 9 and hydrolysis of 3-nitro-1H-1,2,4-triazole derivative 12 with labelled water in the presence of a strong base. The ¹⁵N- and ¹⁷O-NMR spectra of 15 in phosphate-buffered water serve as references for heteronuclear NMR spectra of labelled RNA fragments.