ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Synthesis of Imidazole NucleosidesThe acid-catalyzed fusion of dimethyl imidazole-4,5-dicarboxylate (7) with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (6) provided dimethyl 1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)imidazole-4,5-dicarboxylate (11) as the major product together with some β-anomer (13). The β-anomer (11) was obtained as the only product when the trimethylsilyl derivative (9) of 7 was condensed with 6 in the presence of stannic chloride. Nucleoside 11 was treated with ammonia, and various primary amines to provide 1-β-D-ribofuranosylimidazole-4, 5-dicarbox-amide (5) and N, N'-disubstitued dicarboxamides (18-26) respectively. The synthesis of 1-β-(33) and 1-β-D-arabinofuranosylimidazole-4,5-dicarboxamide (34), is also described. The conformation of 5, as studied by 1H-and 13C-NMR.-spectroscopy, was shown to be very similar to that of adenosine.The oxidation of the 2′,3′-O′-isopropylidene derivative (15) of 5 with potassium permanganate or chromic oxide, followed by deprotection, or the direct oxidation of 5 with oxygen in the presence of platinum catalyst, led to the corresponding 5′-carboxylic acid 36. This was further converted into esters (37 and 38) and amides (39-42).Treatment of some nucleosides with fuming nitric acid in oleum at - 30° yielded the nitric acid esters 43-51. Beside the nitration of their sugar residues, one of the imidazolecarboxamide functions in nucleosides 46-51 and both N-methyl-carboxamide functions in 44 were nitrated. Finally, reaction of the N, N'-dimethyl-N, N'-dinitrodicarboxamide 44 with alkyl- und aralkylamines, afforded the N, N'-dialkyl-and N, N'-diaralkyldicarboxamides 52-56.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19780610843
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