One-pot synthesis of novel 1,2,3-triazole-pyrimido[4,5-c]isoquinoline hybrids and evaluation of their antioxidant activity

<p>A series of novel pyrimido[4,5-<i>c</i>]isoquinolines (<b>3a–3h</b>) and 1,2,3-triazole-coupled pyrimido[4,5-<i>c</i>]isoquinolines (<b>4a–4h</b>) were synthesized in good to excellent yields in the one-pot method. The reaction of 6-amino-1,3-dimethyluracil with different 2-iodo benzoyl chlorides using Pd catalyst in dimethylformamide afforded corresponding pyrimido[4,5-<i>c</i>]isoquinolines (<b>3a–3h</b>). One-pot reaction of pyrimido[4,5-<i>c</i>]isoquinolines with propargyl bromide and benzyl azide in THF at room temperature furnished 1,2,3-triazole-coupled pyrimido[4,5-<i>c</i>]isoquinoline (<b>4a–4h</b>). In vitro antioxidant activity examination revealed that compounds <b>4d</b> and <b>4c</b> found to exhibit potent antioxidant activity as compared to the standard drug Trolox with IC₅₀ values 6.02 ± 0.6 and 12.18 ± 0.9 µM, respectively.</p