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

ABSTRACT

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 µM, respectively.

GRAPHICAL ABSTRACT

KEYWORDS:

• 1,2,3-Triazole
• antioxidant activity
• PD-coupling
• pyrimido[4,5-c]isoquinoline

Acknowledgments

Narsimha thanks the Council of Scientific and Industrial Research, New Delhi for the award of a senior research fellowship. The authors are thankful to the Head, Department of Bio-Technology, Kakatiya University, Warangal for providing data of biological activity.

Additional information

Funding

This work was supported by the Council for Scientific and Industrial Research [Grant Number (09/384(0158)/2012-EMR-I)].