6-Azauridine: Crystal structure and conformation of the antileukemia drug

Abstract

Summary The cytostatic nucleoside analog 6-azauridine has been investigated by single-crystal X-ray diffraction. The pseudo-face-centered structure exhibits an extensive branched network of hydrogen bonds connecting ribose moieties and pairwise stacked bases. The packing resembles that in 4-thiouridine, but the glycosidic bond conformation is anti. The riboses are puckered with C(3′) out of the best four-atom plane.