4(R)‐(6‐Chloro‐s‐triazolo[4,3‐b]pyridazinyl‐3)‐1,4‐furanoses 10 and 11, 5(R)‐(6‐chloro‐s‐triazolo[4,3‐b]pyridazinyl‐3)‐1,5‐pyranose 13, and 2(S),3(R)‐dihydro‐5‐(6‐chloro‐s‐triazolo[4,3‐b]pyridazinyl‐3)‐2,3‐O‐isopropylidenefuran (12) were prepared by cyclization of hydrazones 6–9 obtained from 6‐chloro‐3‐hydrazinopyridazine (1) and aldofuranoses 2, 3 and 4, and aldopyranose 5.
Open‐chain C‐nucleosides, 1‐(s‐triazolo[4,3‐x]azinyl‐3)polyols 13–18 were prepared by one‐pot synthesis from hydrazinoazines 20a,c and various D‐aldoses 1–6. No protective groups were required for these transformations. 1‐(s‐Triazolo[4,3‐b]pyridazinyl‐3)‐D‐xylo‐tetritol (15a) was isolated and characterised in the form of its 4‐O‐triphenylmethyl derivative 19. Reaction of hydrazinopyridazines 20a,b with methyl 2,3‐di‐O‐acetyl‐L‐threuronate (22), followed by treatment with bromine, gave the corresponding (2R,3S)‐2,3‐diacetoxy‐3‐(s‐triazolo[4,3‐b]pyridazinyl‐3)propanoic acid methyl esters 24a,b. Acetonisation of 1‐(6‐chloro‐s‐triazolo[4,3‐b]pyridazinyl‐3)‐D‐gluco‐pentitol (17a) gave a mixture of isomeric bis‐acetonides 25 and 26, while acetonisation of 1‐(6‐chloro‐s‐triazolo[4,3‐b]pyridazinyl‐3)‐D‐manno‐pentitol (18a) gave acetonide 27 as a single isomer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.