SYNTHESIS AND STRUCTURE ASSIGNMENT OF 1-(2-ACETOXYETHOXY) METHYL-DERIVATIVES OF 5-CHLORO-6-AZAURACIL AND 5-BROMO-6-AZAISOCYTOSINE

1-[(2-Acetoxyethoxy)methyl]-5-chloro-6-azauracil has been prepared and its unambiguous assignment of H-1 and C-13 peaks through the H-1-C-13 heteronuclear correlation (HETCOR) NMR experiments is described. The isosteric 1-[(2- acetoxyethoxy)methyl]-5-bromo-6-azaisocytosine has al so been synthesized. The X-Ray crystallographic analysis reveals unamb iguously the site of glycosylation at N-1 Deacetylation of both acyclo nucleosides provided 5-chloro-1-[(2-hydroxyethoxy)methyl]6-azauracil a nd bromo-1-[(2-hydroxyethoxy)methyl]-6-azaisocytosine respectively. Th eir structures have been well established by the NMR spectra and the e lemental analyses.