ZrOCl₂·8H₂O: a highly efficient catalyst for the synthesis of 1,8‐dioxo‐octahydroxanthene derivatives under solvent‐free conditions

Abstract

ZrOCl 2 ·8H 2 O has been found to be an efficient catalyst for the synthesis of 1,8-dioxo-octahydroxanthenes from aldehydes and 5,5-dimethylcyclohexane-1,3-dione under solvent-free conditions.

Facile and efficient synthesis of xanthenedione derivatives promoted by niobium pentachloride

“…Xanthene derivatives can be prepared by several methods: cyclodehydration (Bekaert et al, 1992), the trapping of benzynes by phenols (Knight & Little, 2001), the palladium-catalysed cyclisation of polycyclic aryltriflate esters (Wang & Harvey, 2002), a simple and efficient procedure for the synthesis of xanthene derivatives through one-pot condensation of 2-naphthol with aryl aldehydes in the presence of niobium pentachloride (Bartolomeu et al, 2014), the condensation of cyclohexane-1,3-diones and aromatic aldehydes in the presence of solid acids (Karami et al, 2013a), amongst others (Horning & Horning, 1946;John et al, 2006;Saini et al, 2006;Zhang & Tao 2008;Zhang & Liu, 2008;Wang et al, 2008;Urinda et al, 2009;Lü et al, 2009;Maleki et al, 2011;Soleimani et al, 2011;Pramanik & Bhar, 2012;Dharma Rao et al, 2012;Karami et al, 2013bKarami et al, , 2013aKarami et al, , 2014Li et al, 2013;Cao et al, 2013;Shirini et al, 2013;Iniyavan et al, *Corresponding author, e-mail: lcsilva@fc.unesp.br 2014; Shirini et al, 2014Shirini et al, , 2015Preetam et al, 2015;Ilangovan et al, 2011). However, some of these methods involve long reaction times, extreme reaction conditions, expensive reagents and unsatisfactory yields, hence the improvement of these syntheses has been the target of several studies.…”

Novel CuFe2O4@SiO2‐OP2O5H magnetic nanoparticles: Preparation, characterization and first catalytic application to the synthesis of 1,8‐dioxo‐octahydroxanthenes

“…Also, xanthenes, in particular xanthenediones, have received great attention because of their wide range of biological properties, their use in laser technologies and their presence in dyes . Xanthenediones are generally synthesized by condensation of aromatic aldehydes with 5,5‐dimethyl‐1,3‐cyclohexanedione (dimedone) using various promoting agents …”

[Et3NH][HSO4] catalyzed efficient and green synthesis of 1,8-dioxo-octahydroxanthenes

“…Many synthetic methods for preparing xanthenediones have been reported by the condensation of aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione in the presence of [1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo [2,2,2]octane bis(tetrafluoroborate) [5], montmorillonite K10 [6], pdodecylbenzenesulphonic acid [7], alumina-sulfuric acid [8], trimethylsilyl chloride [9], NaHSO 4 -SiO 2 [10], ZnO-acetyl chloride [11], PMA-SiO 2 [12], NBS [13], Amberlyst-15 [14], Dowex-50W [15], PPA-SiO 2 [16], ZrOCl 2 ·8H 2 O [17], trichloroisocyanuric acid [18], silica sulfuric acid [19], heteropolyacid supported MCM-41 [20], silica bonded N-propyl sulfamic acid [21], nanosized MCM-41-SO 3 [33], respectively. Each of these methods have their own advantages but also suffer from one or more disadvantages such as prolonged reaction time, low yields, use of hazardous or expensive catalysts, use of organic solvents, tedious work-up processes, the requirement of special apparatus, and difficulty in recovery and reusability of the catalysts.…”