122283-23-2Relevant articles and documents
Lewis Acid Catalyzed Reductive Cyclization of 2-Aryloxybenzaldehydes and 2-(Arylthio)benzaldehydes to Unsubstituted 9H-Xanthenes and Thioxanthenes in Diisopropyl Ether
Verma, Shashi Kant,Prajapati, Anamika,Saini, Manoj Kumar,Basak, Ashok K.
supporting information, p. 532 - 539 (2020/11/30)
Readily accessible 2-aryloxybenzaldehydes and 2-(arylthio)benzaldehydes undergo a sequence of reactions leading to a wide variety of unsubstituted 9H-xanthenes and thioxanthenes in high yields when heated with a Lewis acid in diisopropyl ether. This reductive cyclization method is compatible with several important functional groups. The method is also applicable for the selective reductive cyclization of the more electron-rich aryl ring of a 2,6-bis(aryloxy)benzaldehyde. The key feature of this transformation is the chemoselective reduction of a transient xanthylium ion in the presence of aldehydic group via intermolecular hydride transfer from diisopropyl ether (solvent). (Figure presented.).
Metal-free oxidative coupling: Xanthone formation via direct annulation of 2-aryloxybenzaldehyde using tetrabutylammonium bromide as a promoter in aqueous medium
Rao, Honghua,Ma, Xinyi,Liu, Qianzi,Li, Zhongfeng,Cao, Shengli,Li, Chao-Jun
supporting information, p. 2191 - 2196 (2013/10/01)
A metal-free intramolecular annulation of 2-aryloxybenzaldehydes to xanthones is disclosed, which proceeds through the direct oxidative coupling of an aldehyde C-H bond and aromatic C-H bonds using tetrabutylammonium bromide (TBAB) as a promoter in aqueous medium. This strategy works smoothly in the presence of both electron-donating and electron-withdrawing groups, and displays good tolerance towards catalytically reactive substituents, thus promising further functionalizations of xanthone products.
NOVEL ACYL GUANIDINE DERIVATIVES
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Page/Page column 26, (2011/04/24)
The present invention provides a pharmaceutical which possesses an excellent inhibitory effect on NHE3 (Na+/H+ exchanger type 3) and effectively improves diseases or conditions of organs in which NHE3 is expressed.