Pyridothienopyrimidine Derivatives in Antimicrobial Research: A Review Article on Synthetic Strategies and Therapeutic Potential Against Drug‐Resistant Pathogens

Pyridothienopyrimidine derivatives have emerged as an important class of fused heterocyclic compounds due to their structural versatility and promising antibacterial properties. This review article explores the synthesis and antibacterial applications of pyridothienopyrimidine compounds, a class of heterocyclic molecules with growing relevance in medicinal chemistry. It consolidates key synthetic pathways developed over the past two decades, detailing reaction mechanisms and structural modifications aimed at improving antimicrobial effectiveness. Special attention is given to antibacterial studies targeting gram‐positive, gram‐negative, and multidrug‐resistant strains, with comparative assessments against standard antibiotics. Reported SAR trends highlight that cyclization, sulfur substitution, amino acid conjugation, and heterocyclic extensions significantly enhance antibacterial potency, whereas parent scaffolds generally show limited activity. Only those structure–activity relationship (SAR) findings that are explicitly reported in original literature have been included, ensuring accuracy and clarity. To the best of my knowledge, this is the first review article to present a combined analysis of both the synthetic strategies and antibacterial activity of pyridothienopyrimidine derivatives. By highlighting their chemical versatility, promising bioactivity, and structural features linked to higher potency, this review offers valuable insights for researchers focused on drug discovery, antimicrobial resistance(AMR), and heterocyclic scaffold development.