Synthesis of 1,2,4-Triazole C-Nucleosides from Hydrazonyl Chlorides and Nitriles

Abstract

A series of 1,3-diaryl-5-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-1H-1,2,4-triazole nucleosides (3a–f) were synthesized via the intermolecular cyclization of hydrazonyl chlorides with peracylated ribofuranosyl cyanide catalyzed by Yb(OTf)₃ or AgNO₃, respectively. Similarly, the 1,2,4-triazole of glucopyranosyl C-nucleosides 5a,b were prepared from the hydrazonyl chlorides and the nitrile 4. Alternatively, the 1,2,4-triazole N-nucleoside 8 was obtained from cyclization of the unsymmetrical bis[α-(4-methoxyphenyl)aminobenzylidene]-hydrazine with peracylated 1-amino-D-manno-pentitol.

Keywords:

• Hydrazonyl chlorides
• C-nucleosides
• pharmacological activity
• 1,2,4-triazoles