Quinazolines [a]-Annelated by Five-Membered Heterocycles: Synthesis and Biological Activity

This review covers article and patent data obtained mostly within the period 2013–2024 on the synthesis and biological activity of quinazolines [a]-annelated by five-membered heterocycles. Pyrrolo-, (iso)indolo-, pyrazolo-, indazolo-, (benz)imidazo-, (benz)thiazolo-, and triazolo- [a]quinazoline systems have shown multiple potential activities against numerous targets. We highlight that most research efforts are directed to design of anticancer, antibacterial, anti-inflammatory, and other agents of azolo[a]quinazoline nature. This review emphases both the medicinal chemistry aspects of pyrrolo[a]-, (iso)indolo[a]-, and azolo[a]quinazolines and the comprehensive synthetic strategies of quinazolines annelated at the N(1)–C(2) bond from the perspective of drug development and discovery.