Synthesis and spectral studies on some tetrahydrobenzoxanthen-11-ones: crystal and molecular structure of 9,9-dimethyl-12-(2-nitrophenyl)-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one

Abstract

Synthesis and spectral studies on some tetrahydrobenzoxanthen-11-ones: crystal and molecular structure of 9,9-dimethyl-12-(2-nitrophenyl)-8,9,10,12-tetrahydrobenzo[a]xanthen-11-oneAbstract A series of 12-aryl-8,9,10,12-tetrahydrobenzo[a]-xanthen-11-ones have been synthesized by the multicomponent reaction (MCR) of b-naphthol, aryl aldehydes, and dimedone by using BF 3 :OEt 2 as a catalyst. The derived compounds have been analyzed by IR, NMR (1D and 2D), and mass spectra. The single crystal X-ray structural analysis of 9,9-dimethyl-12-(2-nitrophenyl)-8,9,10,12-tetrahydrobenzo[a]-xanthen-11-one evidences the envelope conformation of the cyclohexane ring and the pyran ring tends to adopt flattened-boat conformation.

Natural Organic Acid as Green Catalyst for Xanthenones Synthesis: Methodology, Mechanism and Calcium Channel Blocking Activity

“…8,11,16,17,19,23 The protocols using microwave radiation lasted less than 5-15 min; 15,18,22 however, these methodologies have disadvantages such as the need to prepare the catalysts, 18,22 the use of detrimental metals as catalysts, 15,22 and the use of toxic solvents to purify the desirable products. 15 Our protocol takes only a few minutes to complete the reaction, uses a cheap, eco-friendly and user-friendly catalyst and all the xanthenones were purified by recrystallization.…”

“…7 Many Lewis or Brönsted acids may be used as catalysts: calixarenes, 3 ceric ammonium nitrate, 4 polyethyleneglycol bound sulfonic acid, 5 Hy zeolite, 6 triflate proline, 8 tetrabutyl ammonium fluoride, 9 tri-methyl tetradecyl ammonium bromide, 10 sulfamic acid, 11 p-toluenesulfonic acid, 12 triphenylphosphinem-sulfonate/carbon tetrabromide, 13 phosphorus(V) oxide, cumbersome product isolation procedures. 16 They also use expensive and/or detrimental metal precursors, 14,15,22 toxic catalysts, 11,14 and toxic organic solvents to perform the reaction or purify the product. 13,16,17,20 A readily available and non-hazardous catalyst that promotes the formation of xanthenones in a short reaction time, under solvent-free condition, and simple work-up is highly desirable.…”

“…16 They also use expensive and/or detrimental metal precursors, 14,15,22 toxic catalysts, 11,14 and toxic organic solvents to perform the reaction or purify the product. 13,16,17,20 A readily available and non-hazardous catalyst that promotes the formation of xanthenones in a short reaction time, under solvent-free condition, and simple work-up is highly desirable.…”

Interplay of thermochemistry and Structural Chemistry, the Journal (volume 22, 2011, issues 1–3) and the discipline

“…Sethukumar et al [179] studied multicomponent reaction with the purpose to develop a general approach to the rapid and efficient synthesis of structurally diverse benzoxanthenes. A series of 12-aryl-8,9,10,12-tetrahydrobenzo[a]-xanthen-11-ones which were characterized by spectroscopic methods has been synthesized and characterized by spectroscopic methods.…”

An efficient KHSO4 catalyzed synthesis of xanthenes

“…Xanthenes derivatives have also been synthesized using solvents and Sr(OTf) 2 (Li et al , 2008 ), NaHSO 4 -SiO 2 (Das et al , 2007 ), BF 3 -OEt 2 (Sethukumar et al , 2011 ), prolinetrifl ate (Li et al , 2010 ), and TBAF (Gao et al , 2009 ) as catalysts. Xanthenes have also been obtained in the presence of ionic liquid (Khurana and Magoo , 2009 ) and surfactantcombined catalyst (Shinde et al , 2011 ), However, in spite of their potential utility, many of these methods suffer drawbacks such as unsatisfactory product yields, expensive catalysts, and prolonged reaction times.…”