Xanthene

About: Xanthene is a research topic. Over the lifetime, 2132 publications have been published within this topic receiving 34803 citations. The topic is also known as: Xanthene & dibenzo[a,e]pyran.

One-pot synthesis and UV-Visible absorption studies of novel tricyclic heterocycle tethered Xanthene-1,8-diones

Abstract: A series of new tricyclic heterocyclic xanthene-1,8-diones tethered with chromophoric dibenzo [b, d]furan, dibenzo[b, d]thiophene and 9-methyl-9H-carbazoles were synthesized through one-pot condensation of dibenzo[b, d]furan-2-carbaldehyde, dibenzo[b, d] thiophene-2-carbaldehyde and 9-methyl-9H-carbazole-3-carbaldehyde with cyclic 1,3-dicarbonyls in the presence of recyclable PPA-SiO2 catalyst under solvent-free conditions Further, UV-Visible absorption properties of all the synthesized compounds were investigated in CHCl3, THF and acetonitrile

Synthesis and Electrochromic Properties of Conducting Polymers Based on Highly Planar 2,7-Disubstituted Xanthene Derivatives.

Abstract: On the basis of preliminary DFT calculations, p-type semiconducting polymers based on 2,7-substituted xanthene building blocks that show a high degree of planarity were designed. The synthesis, electrochemical characterization, and theoretical modeling of 2,7-bis(thiophen-2-yl)-9,9-dimethylxanthene (1) and 2,7-bis(3-hexylthiophen-2-yl)-9,9-dimethylxanthene (2) is described. The synthetic procedure is based on the incorporation of thiophene rings by means of Pd-catalyzed cross-coupling reactions, which lead to monomers 1 and 2. Copolymers P1 and P2 obtained by means of anodic polymerization have been characterized by spectroscopic and electrochemical methods. Electrochromism was observed for both polymers. The experimental data supported by density functional theory modeling explain the influence of alkyl chain substitution on the properties of the investigated copolymers.

Zur Dimerisierung des 2-Methyl-1,4-naphthochinons in saurer Lösung

Abstract: 2-Methyl-1,4-naphthochinon 5 dimerisiert beim Erwarmen mit konz. Salzsaure zum rubinroten 1-Methyl-2,7-dihydroxy-dibenzo-[c:h]-10-oxonia-anthracen-chlorid 1. Die Reaktionsbedingungen und der Mechanismus werden aufgezeigt. Wird ein Alkohol als Solvens gewahlt, so entstehen die teilsweise alkylveratherten Farbprodukte 2 – 4 bzw. 11. 1 reagiert mit Basen zum farblosen Xanthen-Derivat 20 bzw. 19. Acetylieren von 1 fuhrt zum gleichfalls farblosen Xanthen-Derivat 22. The Dimerisation of 2-Methyl-1,4-naphthoquinone in Acid Solution 2-Methyl-1,4-naphthoquinone 5 heated with conc. hydrochloric acid dimerises to the red 1-methyl-2,7-dihydroxy-dibenzo-[c;h]-10-oxonia-anthracene-chloride 1. The conditions and the mechanism of the reaction are shown. In alcoholic solutions 1 and the corresponding alkylethers 2 – 4 or 11 are formed. 1 reacts under alkaline conditions to the colourless xanthene derivative 20 or 19. Acetylation of 1 gives the colourless xanthene derivative 22.

Synthetic method of 12-phenyl-benzo[b] xanthenetrione derivative

Abstract: The invention relates to the synthesis of a 12-phenyl-benzo[b] xanthenetrione derivative, and especially relates to the synthesis of 3, 4-dihydro-12-phenyl-2H-benzo[b] xanthene -1, 6, 11 (12H)-trione, which is produced by subjecting the raw materials of aldehyde, 2-hydroxy-1, 4-naphthoquinone and an annular 1, 3-dicarbonyl compound to a one-step reaction by a three component one-pot synthesis method. With simple synthetic process and mild condition, the method of the invention has an overall yield over 80%.