catalyst for the synthesis of 14-aryl- 14-H-dibenzo[aj]xanthenes Silica supported ammonium dihydrogen phosphate （NH4H2PO4/SiO2） is found to be a recyclable heterogeneous catalyst for a rapid and efficient synthesis ...catalyst for the synthesis of 14-aryl- 14-H-dibenzo[aj]xanthenes Silica supported ammonium dihydrogen phosphate （NH4H2PO4/SiO2） is found to be a recyclable heterogeneous catalyst for a rapid and efficient synthesis of various aryl-14-H-dibenzo[a,j]xanthenes with excellent yields under solvent-free conditions. The present methodology offers several advantages such as excellent yields, simple procedure, short reaction times and milder conditions. 2009 Shahnaz Rostamizadeh. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
A simple and efficient procedure for the preparation of aryl- 14-H-dibenzo [aj]xanthenes by a one-pot condensation reaction of 2-naphthol and aryl aldehydes, in the presence of silica supported sodium hydrogen sulfate...A simple and efficient procedure for the preparation of aryl- 14-H-dibenzo [aj]xanthenes by a one-pot condensation reaction of 2-naphthol and aryl aldehydes, in the presence of silica supported sodium hydrogen sulfate （NaHSO4/SiO2） as a catalyst and in the absence of solvent has been developed. The present method offers several advantages such as excellent yields, short reaction time （10-30min）, mild condition, simple work-up, and the use of a cheap and environmentally friendly catalyst with remarkable reusability.展开更多
Fe（HSO4）3 has been used as an efficient and recyclable catalyst for the one-pot synthesis of 14-aryl- or alkyl-14Hdibenzo[aj]xanthene derivatives by the reaction of 2-naphtol and aldehydes. Different types of aromat...Fe（HSO4）3 has been used as an efficient and recyclable catalyst for the one-pot synthesis of 14-aryl- or alkyl-14Hdibenzo[aj]xanthene derivatives by the reaction of 2-naphtol and aldehydes. Different types of aromatic and aliphatic aldehydes are used in the reaction and in all cases the products were obtained in good to excellent yields.展开更多
Various xanthenes have been synthesized by the condensation ofβ-naphthol,2-hydroxynaphthalene-1,4-dione or dimedone with various aldehydes in the presence of trifluoroacetic acid as catalyst in 1,1,3,3-N,N,N′,N′-te...Various xanthenes have been synthesized by the condensation ofβ-naphthol,2-hydroxynaphthalene-1,4-dione or dimedone with various aldehydes in the presence of trifluoroacetic acid as catalyst in 1,1,3,3-N,N,N′,N′-tetramethylguanidinium trifluoroacetate （TMGT） ionic liquid within 1 h at 75℃.展开更多
A simple, efficient, and environment benign route was developed for the preparation of bis-（indolyl）methanes and 14-aryl-14H- dibenzo[aj]xanthenes from condensation of various aromatic aldehydes or ketones with indo...A simple, efficient, and environment benign route was developed for the preparation of bis-（indolyl）methanes and 14-aryl-14H- dibenzo[aj]xanthenes from condensation of various aromatic aldehydes or ketones with indole, and 2-naphthol, respectively, using oxalic acid catalyst in aqueous medium. Use of cheap and easily available catalyst, better yields and simple reaction protocol are the advantages of the present method.展开更多
A new Bronsted acidic ionic liquid, L-Pyrrolidine-2-carboxylic acid sulfate (LPCAS) was employed to promote one-pot synthesis of 14-aryl-14H-dibenzo [a,j] xanthenes via condensation reaction of aldehydes and 2-naphtho...A new Bronsted acidic ionic liquid, L-Pyrrolidine-2-carboxylic acid sulfate (LPCAS) was employed to promote one-pot synthesis of 14-aryl-14H-dibenzo [a,j] xanthenes via condensation reaction of aldehydes and 2-naphthol under solvent free condition. Distinguishing features of the methodology are excellent yield of products in shorter reaction time, cleaner reaction profile, eco-friendly nature and the use of inexpensive catalyst.展开更多
The 1,4-diazabicyclo[2.2.2]octane（DABCO） catalyzed reaction of cyclohexane-1,3-dione or dimedone with various aldehydes in acetonitrile resulted in the polysubstituted tetraketones, spiro dihydrofurans or 1,8-dioxo-...The 1,4-diazabicyclo[2.2.2]octane（DABCO） catalyzed reaction of cyclohexane-1,3-dione or dimedone with various aldehydes in acetonitrile resulted in the polysubstituted tetraketones, spiro dihydrofurans or 1,8-dioxo-xanthenes derivatives as main products respectively according to the structure of reactants and reaction conditions.展开更多
A novel polyamide containing xanthene structure and trifluoromethylphenoxy pendent was prepared from 9,9-bis[4-(4- aminophenoxy)phenyl]xanthene,a novel diamine with 2-(4-trifluoromethylphenoxy)terephthaloyl chloride,b...A novel polyamide containing xanthene structure and trifluoromethylphenoxy pendent was prepared from 9,9-bis[4-(4- aminophenoxy)phenyl]xanthene,a novel diamine with 2-(4-trifluoromethylphenoxy)terephthaloyl chloride,by the low temperature polycondensation.This new polyamide with the inherent viscosity of 0.95 dL/g was amorphous and readily soluble in polar solvents such as DMAc,m-cresol,etc.This polyamide showed the glass transition temperature(T_g) of 236℃,decomposition temperature (Td) at 5%weight loss of...展开更多
A new fluorinated poly(ether amide) bearing xanthene group was prepared from 9,9-bis[4-(2-trifluoromethyl-4-aminophenox- y)phenyl]xanthene (BTFAPX) with 9,9-bis[4-(4-carboxyphenoxy)phenyl]xanthene (BCAPX) in the prese...A new fluorinated poly(ether amide) bearing xanthene group was prepared from 9,9-bis[4-(2-trifluoromethyl-4-aminophenox- y)phenyl]xanthene (BTFAPX) with 9,9-bis[4-(4-carboxyphenoxy)phenyl]xanthene (BCAPX) in the presence of triphenyl phos- phate and pyridine (Py). The polymer had the weight-average molecular weight (Mw) of 69,000 and number-average molecular weight (Mn) of 39,000, showed the glass transition temperature (Tg) of 267 ℃, 5% weight loss temperature (Tds) over 460 ℃ both in N2 and air, and char yield of 62% at 800 ℃ in N2. This polymer was amorphous and readily soluble in amide-type solvents such as N,N-dimethylacetamide (DMAc), and even in m-cressol, Py and tetrahydrofuran (THF) at room temperature, and exhibited tensile strength of 74 MPa, elongation at break of 6%, tensile moduli of 2.2 GPa. The polymer had low dielectric constant of 3.69 (100 Hz), low moisture absorption of 0.56%, and high transparency with an ultraviolet-visible absorption cut-off wavelength at 334 nm.展开更多
Spectrophotometric determination of molybdenum, zinc, cobalt(Ⅱ), indium, selenium (Ⅳ), iron (Ⅲ), vanadium (Ⅴ), which is based on the ion-associate complexes formed by the reaction of metal ion-thiocyanate anionic ...Spectrophotometric determination of molybdenum, zinc, cobalt(Ⅱ), indium, selenium (Ⅳ), iron (Ⅲ), vanadium (Ⅴ), which is based on the ion-associate complexes formed by the reaction of metal ion-thiocyanate anionic complexes with some basic dyes in aqueous solution in the presence of a surfactant has been reported.展开更多
After comparing the influences of each rare earth(Ⅲ),11 species of metal(Ⅱ)and 8 species of acidic triphenylmethane dye on the formation of coloured coordination compound in the system of Metal(Ⅱ)-RE (Ⅲ)-Dye,it wa...After comparing the influences of each rare earth(Ⅲ),11 species of metal(Ⅱ)and 8 species of acidic triphenylmethane dye on the formation of coloured coordination compound in the system of Metal(Ⅱ)-RE (Ⅲ)-Dye,it was proven that the co-colouration effect can be caused only by the xanthene dyes(XD)con- taining substituting hydroxy.group on the ortho-position of etheric oxygen group.Besides,the radius of met- al(Ⅱ)must not be smaller than a definite limit;otherwise,no co-colouration appears.Furthermore,the acid- ity of medium is another important factor to affect co-colouration,Bromopyrogallol red causes co-colouration of Pb(Ⅱ)-RE(Ⅲ)only,owing to its higher chromophoric acidity;while alizarin violet causes co-colouration of M(Ⅱ)-RE(Ⅲ)(M=Pb,Ca,Sr and Ba),due to its lower chromophoric acidity.The condi- tions causing co-colouration,the regularities of co-colouration and the influences of co-colouration in photometric determination of metals were discussed.展开更多
The crystal structure of the title compound (C20H20O4, Mr = 324.36) has been determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Pbcn with a = 15.823(2), b = 18.002(3), c = 11...The crystal structure of the title compound (C20H20O4, Mr = 324.36) has been determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Pbcn with a = 15.823(2), b = 18.002(3), c = 11.674(2) ?, V = 3325.34(67) ?3, Dc = 1.296 g/cm3, μ = 0.090 mm-1, Z = 8, F(000) = 1376, the final R = 0.0421 and wR = 0.0996. In the molecular structure, the pyran ring is of boat conformation, and the two six-membered rings fused with it adopt twisting-boat conformations.展开更多
文摘catalyst for the synthesis of 14-aryl- 14-H-dibenzo[aj]xanthenes Silica supported ammonium dihydrogen phosphate （NH4H2PO4/SiO2） is found to be a recyclable heterogeneous catalyst for a rapid and efficient synthesis of various aryl-14-H-dibenzo[a,j]xanthenes with excellent yields under solvent-free conditions. The present methodology offers several advantages such as excellent yields, simple procedure, short reaction times and milder conditions. 2009 Shahnaz Rostamizadeh. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金the K.N.Toosi University of Technology Research Council for financial support.
文摘A simple and efficient procedure for the preparation of aryl- 14-H-dibenzo [aj]xanthenes by a one-pot condensation reaction of 2-naphthol and aryl aldehydes, in the presence of silica supported sodium hydrogen sulfate （NaHSO4/SiO2） as a catalyst and in the absence of solvent has been developed. The present method offers several advantages such as excellent yields, short reaction time （10-30min）, mild condition, simple work-up, and the use of a cheap and environmentally friendly catalyst with remarkable reusability.
文摘Fe（HSO4）3 has been used as an efficient and recyclable catalyst for the one-pot synthesis of 14-aryl- or alkyl-14Hdibenzo[aj]xanthene derivatives by the reaction of 2-naphtol and aldehydes. Different types of aromatic and aliphatic aldehydes are used in the reaction and in all cases the products were obtained in good to excellent yields.
基金the financial support of the Research Council of the University of Isfahan.
文摘Various xanthenes have been synthesized by the condensation ofβ-naphthol,2-hydroxynaphthalene-1,4-dione or dimedone with various aldehydes in the presence of trifluoroacetic acid as catalyst in 1,1,3,3-N,N,N′,N′-tetramethylguanidinium trifluoroacetate （TMGT） ionic liquid within 1 h at 75℃.
文摘A simple, efficient, and environment benign route was developed for the preparation of bis-（indolyl）methanes and 14-aryl-14H- dibenzo[aj]xanthenes from condensation of various aromatic aldehydes or ketones with indole, and 2-naphthol, respectively, using oxalic acid catalyst in aqueous medium. Use of cheap and easily available catalyst, better yields and simple reaction protocol are the advantages of the present method.
文摘A new Bronsted acidic ionic liquid, L-Pyrrolidine-2-carboxylic acid sulfate (LPCAS) was employed to promote one-pot synthesis of 14-aryl-14H-dibenzo [a,j] xanthenes via condensation reaction of aldehydes and 2-naphthol under solvent free condition. Distinguishing features of the methodology are excellent yield of products in shorter reaction time, cleaner reaction profile, eco-friendly nature and the use of inexpensive catalyst.
基金Supported by the National Natural Science Foundation of China(No20972132)
文摘The 1,4-diazabicyclo[2.2.2]octane（DABCO） catalyzed reaction of cyclohexane-1,3-dione or dimedone with various aldehydes in acetonitrile resulted in the polysubstituted tetraketones, spiro dihydrofurans or 1,8-dioxo-xanthenes derivatives as main products respectively according to the structure of reactants and reaction conditions.
基金the National Natural Science Foundation of China(No.20664001)the Research Program of Jiangxi Province Department of Education(No.2007-123,GJJ08166 and GJJ09138) for the financial support
文摘A novel polyamide containing xanthene structure and trifluoromethylphenoxy pendent was prepared from 9,9-bis[4-(4- aminophenoxy)phenyl]xanthene,a novel diamine with 2-(4-trifluoromethylphenoxy)terephthaloyl chloride,by the low temperature polycondensation.This new polyamide with the inherent viscosity of 0.95 dL/g was amorphous and readily soluble in polar solvents such as DMAc,m-cresol,etc.This polyamide showed the glass transition temperature(T_g) of 236℃,decomposition temperature (Td) at 5%weight loss of...
基金National Natural Science Foundation of China(No.20664001)the Research Program of Jiangxi Province Department of Education(No.2007-123,GJJ08166 and GJJ09138) for the financial support
文摘A new fluorinated poly(ether amide) bearing xanthene group was prepared from 9,9-bis[4-(2-trifluoromethyl-4-aminophenox- y)phenyl]xanthene (BTFAPX) with 9,9-bis[4-(4-carboxyphenoxy)phenyl]xanthene (BCAPX) in the presence of triphenyl phos- phate and pyridine (Py). The polymer had the weight-average molecular weight (Mw) of 69,000 and number-average molecular weight (Mn) of 39,000, showed the glass transition temperature (Tg) of 267 ℃, 5% weight loss temperature (Tds) over 460 ℃ both in N2 and air, and char yield of 62% at 800 ℃ in N2. This polymer was amorphous and readily soluble in amide-type solvents such as N,N-dimethylacetamide (DMAc), and even in m-cressol, Py and tetrahydrofuran (THF) at room temperature, and exhibited tensile strength of 74 MPa, elongation at break of 6%, tensile moduli of 2.2 GPa. The polymer had low dielectric constant of 3.69 (100 Hz), low moisture absorption of 0.56%, and high transparency with an ultraviolet-visible absorption cut-off wavelength at 334 nm.
基金Supported by the National Natural Science Foundation of China
文摘Spectrophotometric determination of molybdenum, zinc, cobalt(Ⅱ), indium, selenium (Ⅳ), iron (Ⅲ), vanadium (Ⅴ), which is based on the ion-associate complexes formed by the reaction of metal ion-thiocyanate anionic complexes with some basic dyes in aqueous solution in the presence of a surfactant has been reported.
文摘After comparing the influences of each rare earth(Ⅲ),11 species of metal(Ⅱ)and 8 species of acidic triphenylmethane dye on the formation of coloured coordination compound in the system of Metal(Ⅱ)-RE (Ⅲ)-Dye,it was proven that the co-colouration effect can be caused only by the xanthene dyes(XD)con- taining substituting hydroxy.group on the ortho-position of etheric oxygen group.Besides,the radius of met- al(Ⅱ)must not be smaller than a definite limit;otherwise,no co-colouration appears.Furthermore,the acid- ity of medium is another important factor to affect co-colouration,Bromopyrogallol red causes co-colouration of Pb(Ⅱ)-RE(Ⅲ)only,owing to its higher chromophoric acidity;while alizarin violet causes co-colouration of M(Ⅱ)-RE(Ⅲ)(M=Pb,Ca,Sr and Ba),due to its lower chromophoric acidity.The condi- tions causing co-colouration,the regularities of co-colouration and the influences of co-colouration in photometric determination of metals were discussed.
文摘The crystal structure of the title compound (C20H20O4, Mr = 324.36) has been determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Pbcn with a = 15.823(2), b = 18.002(3), c = 11.674(2) ?, V = 3325.34(67) ?3, Dc = 1.296 g/cm3, μ = 0.090 mm-1, Z = 8, F(000) = 1376, the final R = 0.0421 and wR = 0.0996. In the molecular structure, the pyran ring is of boat conformation, and the two six-membered rings fused with it adopt twisting-boat conformations.
