23783-79-1Relevant academic research and scientific papers
Microwave assisted one pot synthesis of 7-substituted 2-(2-oxo-2H-chromen-3-yl)acetic acids as precursors of new anti-tumour compounds
Kovacova, Silvia,Kovacikova, Lucia,Lacova, Margita,Bohac, Andrej,Salisova, Marta
experimental part, p. 806 - 811 (2011/11/06)
Perkin condensation with subsequent intramolecular lactonisation as one pot syntheses of 2-(2-oxo-2H-chromen-3-yl)acetic acids VIIa-Xa has been studied. The required acids VIIa-Xa were prepared as precursors of recently discovered compounds possessing antineoplastic activities. Syntheses of VIIa-Xa were carried out using para substituted 2-hydroxybenzaldehydes II-VI, succinic acid anhydride, sodium succinate under thermal or microwave conditions. Significant shortening of the reaction time under microwave irradiation was observed (18-50 min instead of 1.5-5 h of heating). Microwave assisted reactions proceeded more smoothly to give higher yield of the required products VIIa-Xa (31-61 %) compared to those under classical thermal conditions e.g. 21.8 % for IXa (Hurenkamp et al., 2007). Seven reaction by-products were isolated and determined as 2H,2′H-3,3′-bichromene-2,2′-diones VIIb-Xb and (E)-3-(2-hydroxystyryl)-2H-chromen-2-ones VIIc-IXc.
A new gold-catalyzed domino cyclization and oxidative coupling reaction
Wegner, Hermann A.,Ahles, Sebastian,Neuburger, Markus
supporting information; experimental part, p. 11310 - 11313 (2009/10/17)
Gold-catalyzed domino cyclization and oxidative coupling reaction for synthesis of dicoumarins was studied. Gold was thought to be an unreactive metal before its catalyzed reaction was discovered. HAuCl4 was suspended in dry 1,2-dichloroethane (DCE), whereas protic solvent gave only monomer and UV absorption and fluorescence properties of dicoumarins were similar to those of monomers. The crude product was purified by flash column chromatography on silica and gold catalyst performed two different functions. Dicoumarins, scaffolds of natural products has interesting biological properties whereas, potential photostable UV-absorbent materials were accessed in two steps from commercially available starting materials. The reaction generally proceeded in moderate-to-good yields, tolerating a variety of substituents on the aromatic moiety.
