Synthesis and X-ray structural studies of 5-methyl-6-nitro-7-oxo-4,7-dihydro-1,2,4-triazolo[1,5-а]pyrimidine L-arginine and piperidine salts

Abstract

The previously described L-argininium 5-methyl-6-nitro-7-oxo-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidinide monohydrate and piperidinium 5-methyl-6-nitro-7-oxo-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidinide, which has not been described previously, were synthesized as promising antiviral drugs. A detailed comparison of the crystal structures of these two compounds was performed. It is shown that the replacement of the L-arginine cation with piperidinium one leads to a serious reorganization of the system of intermolecular hydrogen bonds in the solid state, which, in our opinion, can have a significant impact on the interaction of the new drug with biological targets. Thus, by comparing the X-ray structural analysis data, the probability of the influence of the nature of the counterion on the biological effect of the drug was demonstrated.