A Comprehensive Review of Azolo[d]pyrimidines Derived from Pyrimidine with Potential Biological Applications: Part I - One-Nitrogen Azoles

Abstract:

This review highlights the pyrimidine ring as a highly versatile and valuable core scaffold for the construction of fused azolo[d]pyrimidine systems, particularly pyrrolo[d]pyrimidines containing a single nitrogen atom within the azole ring (part-1). Fusion of a pyrrole moiety with the pyrimidine nucleus gives rise to structurally diverse regioisomeric frameworks, namely pyrrolo[2,3-d]pyrimidines (9-deazaguanines), pyrrolo[ 3,2-d]pyrimidines (7-deazapurines), and pyrrolo[3,4-d]pyrimidines, each exhibiting distinct structural characteristics and diverse biological profiles. Collectively, pyrrolo[d]pyrimidines have shown promising biological activities, including anticancer, antimicrobial, and anti-inflammatory effects, underscoring their importance in drug discovery. This review provides a comprehensive overview of their regioisomeric classification, synthetic approaches, recent methodological advances, and emerging biological significance, emphasizing their role as important scaffolds for future medicinal chemistry and pharmaceutical development.