simple, efficient, and environmentally benign route was developed for the preparation of 14-aryl or alkyl-14H-dibenzo[a,j]xanthene, 1,8-dioxo-octahydroxanthene and 12-aryl—8,9,10,12-tetrahydrobenzo[a]xanthene-11-ones from condensation of various aldehydes with (i) β-naphthol, (ii) cyclic 1,3-dicarbonyl compounds and (iii) β-naphthol and cyclic 1,3-dicarbonyl compounds, using novel polymeric catalyst [poly(AMPS-co-AA)]
Rapid, efficient and solvent-free synthesis of (un)symmetrical xanthenes catalyzed by recyclable sulfated polyborate
作者:Manisha S. Patil、Amey V. Palav、Chetan K. Khatri、Ganesh U. Chaturbhuj
DOI:10.1016/j.tetlet.2017.06.027
日期:2017.7
straightforward approach to the synthesis of 1,8-dioxo-octahydroxanthenes, 14-phenyl-14H-dibenzo[a,j]xanthene and tetrahydrobenzoxanthene-11-ones under solvent-free conditions usingsulfated polyborate as a highly efficientcatalyst. The procedure offers several advantages including cleaner reaction profile, mild reaction condition, economic, recyclable and environmentally benign catalyst, high yields, simple
4-Imidazol-1-yl-butane-1-sulfonic acid or a novel liquid salt? The NMR analysis and dual solvent-catalytic efficiency for one-pot synthesis of xanthenes
structure of the product was investigated by the NMRanalysis in CD3OD and DMSO‑d6. This work demonstrated that 4-imidazol-1-yl-butane-1-sulfonic acid could not be obtained through the above reaction and the mixture of zwitterionic (I) and ionic (II) structure is produced. The structure of the liquid salt (I + II) was characterized and analyzed by 2D NMR. Then, the dual solvent-catalytic efficiency of
Phosphoric acid supported on alumina (H3PO4/Al2O3) is an efficient catalyst for the catalytic multi-component condensation reaction and a wide variety of syntheses of benzoxanthene pigments in good yields. The remarkable features of this new procedure are high conversions, shorter reaction times, cleaner reaction, and simple experimental and work-up procedures.
Green multi-component domino reactions (MCRs)1–7 for the synthesis of fine chemicals have attracted much recent interest.8–9 Quinolines, spiro[4H-pyran-oxindoles] and xanthenes are reported as havi...