A practical and green method for the synthesis of 5H-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3′-indoline]-pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (CSA) under solvent-free conditions at 100 °C is described. The significant features of this procedure are high yields of the products, simple […]
A green and convenient méthode for the synthesis of a variety of xanthene derivatives by condensation reaction between aldehydes and β-naphthol or dimedone in an micellar solution of sodium dodecylphosphonate is described. This method offers several advantages, such as using of a cheap and environmentally benign reaction media, low loadings of sodium dodecylphosphonate as catalyst […]
An efficient and simple procedure for the synthesis of 1,8-dioxo-octahydroxanthenes from the aromatic aldehydes and 5,5-dimethylcyclohexane-1,3-dione (dimedone) in the presence of boric acid [BO3H3 or B(OH)3] as an inexpensive and reusable catalyst is described. The salient features of this methodology are: the elimination of corrosive liquid acids, high yields, simple methodology, short reaction times, easy […]
A rapid, green and efficient method for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthene derivatives through a one-pot condensation of 2-naphthol with various aromatic aldehydes in the presences of several acidic ionic liquids including [PSMIM]Cl, [BMIM]HSO4, [BMIM]Cl, [BMIM]Br, and [BMIM]BF4 as organocatalysts and task-specific acidic ionic liquids (AILs) under solvent-free conditions is described. Compared with other synthetic methods, […]
A novel hybrid catalyst based on grafting Cu on furfural imine-functionalized halloysite was designed, characterized and used for promoting synthesis of xanthene derivatives via three- component reaction of benzaldehyde derivatives, dimedone, and β-naphthol in aqueous media and under mild reaction condition. The results established high catalytic activity of the hybrid system, which was superior to […]