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.

The aim of this work was to synthesize selected thiophene-derived aminophosphonic systems and evaluate the phytotoxicity of newly obtained products according to the OECD 208 Guideline. Seven new thiophene-derived N-substituted dimethyl aminomethylphosphonic acid esters 2a–h were synthesized by the addition of an appropriate phosphite to azomethine bond of starting Schiff bases 1a–h, and NMR spectroscopic properties of aminophosphonates were investigated. These eight compounds were analyzed in regard to their phytotoxicity towards two plants, radish (Raphanus sativus) and oat (Avena sativa). On the basis of the obtained results, it was found that tested aminophosphonates 2a–h showed an ecotoxicological impact against selected plants, albeit to various degrees.