1769-25-1Relevant articles and documents
Visible light induced tandem reactions: An efficient one pot strategy for constructing quinazolinones using in-situ formed aldehydes under photocatalyst-free and room-temperature conditions
Xie, Zongbo,Lan, Jin,Zhu, Haibo,Lei, Gaoyi,Jiang, Guofang,Le, Zhanggao
supporting information, p. 1427 - 1431 (2020/11/02)
A facile tandem route has been developed for constructing quinazolinones from various aminobenzamides and in-situ generated aldehydes. Visible light was found to play a dual role: first oxidizes the alcohol to the aldehyde and then facilitates its cyclization with o-substituted aniline. Furthermore, alcohols are perfect alternatives to aldehydes because they are greener, more available, more economical, more stable, and less toxic than aldehydes. The first reaction step continuously provides material for the second step, which effectively reduces loss through volatilization, oxidation, and polymerization of the aldehyde, while avoiding its toxicity. A variety of quinazolinones can be prepared in the presence of visible light without any additional photocatalyst. The developed synthesis protocol proceeds with the merits of mild conditions, broad substrate scope, operational simplicity, and high atom efficiency, with an eco-energy source under metal-free, photocatalyst-free, and ambient conditions.
Synthesis of 2-aryl quinazolinones: Via iron-catalyzed cross-dehydrogenative coupling (CDC) between N-H and C-H bonds
Jang, Yoonkyung,Lee, Seok Beom,Hong, Junhwa,Chun, Simin,Lee, Jeeyeon,Hong, Suckchang
supporting information, p. 5435 - 5441 (2020/08/03)
Herein, we describe the direct synthesis of quinazolinones via cross-dehydrogenative coupling between methyl arenes and anthranilamides. The C-H functionalization of the benzylic sp3 carbon is achieved by di-t-butyl peroxide under air, and the subsequent amination-aerobic oxidation process completes the annulation process. Iron catalyzed the whole reaction process and various kinds of functional groups were tolerated under the reaction conditions, providing 31 examples of 2-aryl quinazolinones using methyl arene derivatives in yields of 57-95percent. The synthetic potential has been demonstrated by the additional synthesis of aryl-containing heterocycles. This journal is
Quinazolin-4(3H)-ones and 5,6-dihydropyrimidin-4(3H)-ones from β-aminoamides and orthoesters
Gavin, Joshua T.,Annor-Gyamfi, Joel K.,Bunce, Richard A.
, (2018/11/24)
Quinazolin-4(3H)-ones have been prepared in one step from 2-aminobenzamides and orthoesters in the presence of acetic acid. Simple 2-aminobenzamides were easily converted to the heterocycles by refluxing in absolute ethanol with 1.5 equivalents of the orthoester and 2 equivalents of acetic acid for 12–24 h. Ring-substituted and hindered 2-aminobenzamides as well as cases incorporating an additional basic nitrogen required pressure tube conditions with 3 equivalents each of the orthoester and acetic acid in ethanol at 110?C for 12–72 h. The reaction was tolerant towards functionality on the benzamide and a range of structures was accessible. Workup involved removal of the solvent under vacuum and either recrystallization from ethanol or trituration with ether-pentane. Several 5,6-dihydropyrimidin-4(3H)-ones were also prepared from 3-amino-2,2-dimethylpropionamide. All products were characterized by melting point, FT-IR, 1H-NMR, 13C-NMR, and HRMS.
