Synthesis, characterisation, crystal structures, anticoagulant and antiplatelet activity studies of new 2,6-dipyrazinylpyridines with pendant trimethoxyphenyl

Abstract Three new 2,2'-[4-(n,n’,n”-trimethoxyphenyl)pyridine-2,6-diyl]dipyrazines (1–3) were synthesised by facile one-pot procedure from 2-acetylpyrazine and n,n’,n”-trimethoxybanzaldehydes in methanol in presence of KOH and ammonia solution. The compounds 1–3 were characterised by 1H and 13C NMR, FT-IR, UV–Visible and fluorescence spectroscopy. The molecular structures of compounds 1, 2 and 3 were also confirmed by single crystal X-ray diffraction. There exists CH⋯N and CH⋯O type intermolecular secondary interactions in the crystalline solids of 1, 2 and 3 resulting in supramolecular structures. These compounds were explored for anticoagulant and antiplatelet studies. All the compounds prolonged the clotting time of citrated human plasma in both PRP and PPP. In PRP, they enhanced clotting time from control by 60–100 Sec whereas in PPP by 80–140 Sec. In addition, 2 inhibited the ADP induced platelet aggregation whereas 1 and 3 did not show any role. The inhibition percentage of 2 was found to be 14. Moreover, these compounds were found non-toxic to RBCs.