An Updated Review on Novel Innovations and Emerging Insights in Quinazoline and Quinazolinone Derivatives

Quinazoline and quinazolinone scaffolds have gained significant attention as versatile pharmacophores for the development of central nervous system (CNS) therapeutics. Their favorable lipophilicity contributes to efficient transport across the blood–brain barrier, a critical requirement for CNS drug candidates. These heterocyclic systems can be prepared using classical synthetic routes such as the Niementowski reaction, Gabriel synthesis, Morgan’s reaction, and the Sen– Ray method. More recently, novel and refined synthetic methodologies have enabled the rational design of structurally diverse derivatives with controlled substitution patterns, leading to enhanced pharmacological performance. Such innovations allow optimization of key drug-like properties, including bioavailability, CNS penetration, and molecular target specificity. Emerging pharmacological studies suggest that several quinazoline and quinazolinone derivatives exert their CNS effects through modulation of the γ-aminobutyric acid type A (GABAA) receptor, an ionotropic chloride channel central to inhibitory neurotransmission. Activation of this receptor increases chloride ion conductance, resulting in neuronal hyperpolarization and reduced excitability. This mode of action aligns with that of many established CNS-active agents, highlighting the therapeutic potential of quinazoline-based compounds in neurological disorder management.