Synthesis of 3-(Tetritol-1-YL)-6-Phenyl-1,2,4-Triazolo[3,4-a]Phthalazines and Conformational Analysis of their Acetates

ABSTRACT

Condensation of 1-hydrazino-4-phenylphthalazine with D-arabinose, L-arabinose, D-lyxose, and D-xylose gave the corresponding 3-(tetritol-l-yl)-6-phenyl-1,2,4-triazolo3,4-a]phthalazines (acyclic C-nucleoside analogs). D-Ribose, on the other hand, reacted with the same hydrazine to give the corresponding aldehydo-D-ribo-(4-phenyl-1-phthalazinyl) hydrazone. Catalytic dehydrogenative cyclization of this hydrazone with palladium-on-charcoal affected its transformation into the corresponding triazolophthalazine. Acetylation of the prepared acyclic C-nucleoside analogs gave the corresponding tetra-O-acetyl derivatives, the conformational analysis of which has been studied using proton magnetic resonance spectroscopy. Results of some biological activities of the prepared compounds are reported.