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

A series of novel pyrimido[4,5-c]isoquinolines (3a-3h) and 1,2,3-triazole-coupled pyrimido[4,5-c]isoquinolines (4a-4h) 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-c]isoquinolines (3a-3h). One-pot reaction of pyrimido[4,5-c]isoquinolines with propargyl bromide and benzyl azide in THF at room temperature furnished 1,2,3-triazole-coupled pyrimido[4,5-c]isoquinoline (4a-4h). In vitro antioxidant activity examination revealed that compounds 4d and 4c 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 mu M, respectively. [GRAPHICS] .