Synthesis and Biofunctional Properties of NaBr/H₂O₂‐Induced Brominated Uracil Derivatives

Abstract

Bromouracil derivatives are synthesized using an environmentally acceptable bromination protocol involving NaBr as a promoter. A minimum of 1.5 equivalent NaBr was required to reach the maximum yield. The reactions were conducted in an acidic medium in the presence of H2O2 under ambient conditions. We successfully synthesized ten novel 5‐bromouracil derivatives available in our laboratory and characterized them using various spectroscopic methods such as 1H‐NMR, 13C‐NMR, and SC‐XRD. All the derivatives are screened for anti‐bacterial activities against gram‐positive and gram‐negative bacteria. In particular, compounds 5‐bromo‐4‐chloro‐6‐methylpyrimidin‐2‐amine and 5‐bromo‐6‐chloropyrimidine‐2,4‐diamine exhibited prominent antibacterial activity against gram‐negative E. coli with IC50 values of ~9.8 and ~5.7 μg/mL. The structural‐activity relationship revealed that the presence of the −NH2 group in both the bromo derivatives affirms improving activity. Molecular docking studies also supported the experimental result and showed good binding energy of −4.4 (2 a) and −4.8 (2 b) kcal/mol against E. coli primase.