Recent Advances in One-Pot Multicomponent Reactions for the Synthesis of Substituted Quinazolin-4(3H)-ones

Quinazolin-4(3H)-ones are nitrogen heterocycles that have attracted considerable interest over many years due to their important biological and pharmacological properties. It has been shown that quinazolinone derivatives exhibit, e.g., analgesic, anti-inflammatory, antibacterial, anticonvulsant, antifungal, and antitumor activities. Some of these compounds have found applications in medicine; for instance, Zydelig (Idelalisib) has been approved for the treatment of several types of blood cancers. Furthermore, the quinazolinone skeleton is an important structural moiety present in many naturally occurring alkaloids, such as Febrifugine, a potent anti-malarial agent. To date, numerous synthetic methods have been developed for the synthesis of quinazolinone derivatives. Among them, multicomponent reactions (MCRs) have emerged as a powerful tool, allowing for the rapid and straightforward construction of the quinazolinone scaffold from readily available substrates. This review article presents a concise overview of selected strategies for synthesizing quinazolinone frameworks via one-pot MCRs. The reported methods are categorized into three main groups: metal-catalyzed reactions; isatoic-anhydride-based strategies, utilizing isatoic anhydride as a key starting material, and alternative approaches involving, among others, the utilization of N-(2-aminobenzoyl)benzotriazoles or aryldiazonium salts as efficient building materials.