Mukaiyama’s reagent promoted mild protocol for one-pot metal-free synthesis of dihydro quinazolinones

Discovery of N-benzyl-6-methylpicolinamide as a potential scaffold for bleaching herbicides

BACKGROUND

In pesticide research, bleaching herbicides have always been a hot topic. Our previous research showed that N-(4-fluorobenzyl)-2-methoxybenzamide is an innovative lead compound for bleaching herbicides.

RESULTS

A total of 40 derivatives of picolinamides were prepared and evaluated for their herbicidal activity by Petri dish tests and postemergence trials. The structure-activity relationship (SAR) revealed that introducing electron-withdrawing groups at the 3- or 4-positions of the benzyl significantly enhances herbicidal activity. Furthermore, ZI-04 induced similar symptoms such as bleaching effect in treated weeds and accumulation of biosynthetic precursors for carotenoids as observed with diflufenican. ZI-04 also exhibited significant cross-resistance to diflufenican and had a lower resistance risk than diflufenican.

CONCLUSION

N-benzyl-6-methylpicolinamides were discovered as a novel scaffold for bleaching herbicides. The accumulation of phytoene, phytofluene and ζ-Carotene in radish cotyledons, and cross-resistance observed with diflufenican, showed that title compounds can interfere with carotenoid biosynthesis. © 2024 Society of Chemical Industry.

Tandem Transformation of Indazolones to Quinazolinones through Pd-Catalyzed Carbene Insertion into an N-N Bond

Serendipitous and expedite transformation of 1-aryl- and 2-aryl-1,2-dihydro-3H-indazol-3-ones to 1,2-di(hetero)aryl- and 2,3-di(hetero)aryl-2,3-dihydroquinazolin-4(1H)-ones, respectively, was achieved in high efficiency by reacting them with aldehydic N-tosylhydrazones. The protocol proceeded through a cascade process involving base-mediated Pd-carbenoid generation by the decomposition of N-tosylhydrazones, nucleophilic attack of indazolone on the Pd-carbenoid complex, and intramolecular ring expansion via N-N bond cleavage. The utility of the strategy is demonstrated toward the synthesis of bioactive NPS 53574, a calcium receptor antagonist.

Copper Catalyst-Supported Modified Magnetic Chitosan for the Synthesis of Novel 2-Arylthio-2,3-dihydroquinazolin-4(1H)-one Derivatives via Chan–Lam Coupling

In this paper, magnetic chitosan is used as a support for the immobilization of copper catalyst (Cu@MChit). The fabricated catalyst is successfully synthesized and characterized by several techniques. The activity of Cu@MChit catalyst is evaluated in the synthesis of novel derivatives of 3-alkyl-2-arylthio-2,3-dihydroquinazolin-4(1H)-ones. The products are synthesized in three simple steps via Chan–Lam coupling reaction. The synthetic route is based on the reaction of isatoic anhydride and an amine, followed by the reaction with carbon disulfide. Cu@MChit-catalyzed reaction of the obtained intermediate with phenylboronic acid leads to the desired products. The scope of the reaction is confirmed by using various amine and phenylboronic acid derivatives and the products are obtained in high isolated yields.