In this paper, the synthesis and characterization of a triarylpyrazoline modified four-H-bonded molecular duplex are described. Its molecular structure has been confirmed by ^1H NMR and ESI-MS. The duplex emits strong...In this paper, the synthesis and characterization of a triarylpyrazoline modified four-H-bonded molecular duplex are described. Its molecular structure has been confirmed by ^1H NMR and ESI-MS. The duplex emits strong pure blue light peaking at 448 and 452 nm under UV photoexcitation in solution and solid state, respectively, and its relative photoluminescence quantum efficiency in solution is determined as 0.778 using quinine sulfate as reference. In concentration of 〉40 mmol/L, the duplex can gelate DMSO, and the organogel formed shows good pure blue photoluminescence too. This novel duplex, for its well-defined structure and efficient photoluminescence property, is a prospective candidate for pure blue electroluminescent emitter.展开更多
Nine complexes of rare earths with 5 phenyl pyrazoline dithioformate, Na[RE(S 2CNC 9H 9 N) 4· x H 2O (RE=La~Dy, Y, except for Ce and Pm) were synthesized in dry N 2 atmosphere and characterized by ...Nine complexes of rare earths with 5 phenyl pyrazoline dithioformate, Na[RE(S 2CNC 9H 9 N) 4· x H 2O (RE=La~Dy, Y, except for Ce and Pm) were synthesized in dry N 2 atmosphere and characterized by elemental analyses, molar conductance, IR spectra, thermal analyses. The results show that the ligands coordinate to the RE ion through two sulphur atom donors. Thermal analyses indicate that the thermal stability of the complex is not higher than that of sodium 5 phenyl pyrazoline dithioformate. The complexes are easily soluble in acetonitrile and tetrahydrofuran. The molar conductance values of the complexes measured in acetonitrile (1 24~1 32×10 -3 mol·dm -3 ) at 25 ℃ are in the range of 86~104 Ω -1 ·cm 2·mol -1 , indicating that they are 1∶1 electrolytes.展开更多
The molecular structures of ground state and first single excited state for pyrazoline derivatives are optimized with DFT B3LYP method and ab initio “configuration interaction with single excitations”(CIS) method,...The molecular structures of ground state and first single excited state for pyrazoline derivatives are optimized with DFT B3LYP method and ab initio “configuration interaction with single excitations”(CIS) method, respectively. The frontier molecular orbital characteristics have been analyzed systematically, and the electronic transition mechanism has been discussed. Electronic spectra are calculated by using TD-DFT method. These results are consistent with those from the experiment.展开更多
Two pyrazoline derivants 1-(2-benzothiazole)-3-phenyl-5-(3-thiophene)-2- pyrazoline (BPTP) and 1-(2-benzothiazole)-3-(2-thiophene)-5-phenyl-2-pyrazoline (BTPP) have been synthe- sized and their crystal structures were...Two pyrazoline derivants 1-(2-benzothiazole)-3-phenyl-5-(3-thiophene)-2- pyrazoline (BPTP) and 1-(2-benzothiazole)-3-(2-thiophene)-5-phenyl-2-pyrazoline (BTPP) have been synthe- sized and their crystal structures were determined by X-ray single-crystal diffraction. Crystal of BPTP belongs to triclinic, space group P1 with a = 9.4430(11), b = 9.9384(13), c = 9.9394(13) ?, α = 83.107(10), β = 79.947(10), γ = 70.221(7)o, V = 862.42(19) ?3, Z = 2, Dc = 1.392 g/cm3, μ(MoKα) = 0.316 mm-1, F(000) = 376, λ = 0.71070 ?, (?ρ)max = 0.348, (?ρ)min = –0.481 e/?3, the final R = 0.0407 and wR = 0.1055 for 2844 observed reflections with I > 2σ(I). Crystal of BTPP is of monoclinic, space group P21/c with a = 11.6158(17), b = 11.2796(18), c = 13.082(2) ?, α = 90, β = 91.087(4), γ = 90o, V = 1713.7(5) ?3, Z = 4, Dc = 1.401 g/cm3, μ(MoKα) = 0.318 mm-1, Mr = 361.07, F(000) = 752, λ = 0.71070 ?, (?ρ)max = 0.322, (?ρ)min = –0.330 e/?3, the final R = 0.0563 and wR = 0.1058 for 3434 observed reflections with I > 2σ(I).展开更多
1,3,5-Trisubstituted pyrazolines were oxidized to the corresponding pyrazoles in high yield with tris(4-bromophenyl)aminium (TBPA**) hexachloroantimonate in chloroform at room temperature.
Three kinds of pyrazolines were designed and synthesized. Their structures were elucidated by IR, (HNMR)-H-1, MS, UV and elemental analysis. Their luminescent properties were determined, which indicated that they had ...Three kinds of pyrazolines were designed and synthesized. Their structures were elucidated by IR, (HNMR)-H-1, MS, UV and elemental analysis. Their luminescent properties were determined, which indicated that they had strong blue fluorescent properties. One of them was designed to have good film formation. All the three kinds of pyrazolines can be used as blue organic electroluminescence materials (OELMs).展开更多
Various recent reports on Tuberculosis have alarmed an increase in the patient class and subsequent death rates across the globe. Over and above the spread of more dangerous and fatal forms of tuberculosis like MDR-TB...Various recent reports on Tuberculosis have alarmed an increase in the patient class and subsequent death rates across the globe. Over and above the spread of more dangerous and fatal forms of tuberculosis like MDR-TB i.e. multiple-drug resistance tuberculosis, XDR-TB i.e. extensively-drug resistance tuberculosis & TDR-TB i.e. total-drug resistance tuberculosis has forwarded an urgent need to discover novel antitubercular agents. The current work is aimed at combining two previously well-known pharmacophores (pyrazoline and benzoxazole nucleus) in order to design and synthesize a series of novel benzoxazole-based pyrazoline derivatives. The synthesized target compounds were structurally confirmed by LCMS, 1H-NMR and 13C-NMR analysis. The target compounds were In vitro evaluated against M. tuberculosis H37Rv strain, multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) strains. The In vitro screening results depicted that majority of the target compounds displayed potent activity with MIC in a range of ~0.8 to 6.25 μg/mL. Many compounds were found to be more potent than isoniazid against MDR-TB with MIC value 3.12 μg/mL and XDR-TB with MIC value 12.5 μg/mL. Cytotoxicity assay of these active compounds on VERO cell lines also displayed good selectivity index.展开更多
Eight new compounds containing in their structures substituted quinoline and pyrazole entity were synthesized in good to excellent yield by cyclocondensation reaction of chalcones and hydrazine hydrate. This reaction ...Eight new compounds containing in their structures substituted quinoline and pyrazole entity were synthesized in good to excellent yield by cyclocondensation reaction of chalcones and hydrazine hydrate. This reaction was conducted in formic acid in presence of BF3·Et2O or in acetic acid. These approaches were extended to bis-chalcones, which delivered functionalized bispyrazolines. The structures of the prepared compounds were confirmed by IR, 1HNMR, 13CNMR and mass spectral analysis.展开更多
b Département de Physique, Ecole Polythechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland c Department of Chemistry, Tsinghua University, Beijing 100084, China An excellent hole-transpor...b Département de Physique, Ecole Polythechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland c Department of Chemistry, Tsinghua University, Beijing 100084, China An excellent hole-transport material, 1,3-diphenyl-5-(9-phenanthryl)-2-pyrazoline (DPPhP) for OLEDs was studied. This compound not only offers high glass transition temperature (T g=96 ℃), good film forming ability, and high HOMO energy level, but also displays excellent hole-transport property. The electroluminescent device with a simple structure of ITO/DPPhP (60 nm)/AlQ (60 nm)/LiF (0.8 nm)/Al shows an external quantum efficiency as high as 1.6%.展开更多
A series of novel 5-phenyl-3-(2,2':5',2″-terthien-5-yl)-4,5-dihydro-lH-pyrazolines were synthesized in this report. Their photoactivated cytotoxicities on the 5podoptera litura (SL) cell line were evaluated us...A series of novel 5-phenyl-3-(2,2':5',2″-terthien-5-yl)-4,5-dihydro-lH-pyrazolines were synthesized in this report. Their photoactivated cytotoxicities on the 5podoptera litura (SL) cell line were evaluated using the MTT method. It was noticed that the inhibitory activities of all the conjugates was enhanced when irradiated with UV-A light. Compounds 4, 6 and 8 were found to be most effective with inhibition rates of 88.1%, 88.0%, and 90,5%, respectively, For compound B, the inhibition rate value was only slightly enhanced under the irradiation treatment (78.3%) compared to the dark treatment (74.8%). The relationship analysis between structure and activity showed that the middle thiophene ring played an important role on the inhibitory activities. It was shown that these compounds could be the potential candidates for new photoactivated pesticides.展开更多
An efficient and facile synthesis of a library of hitherto novel 1,2,3-triazolyl-N-acetyl/N-propionylpyrazoline hybrids (16 examples) in excellent yields (90%-96%) has been accomplished from easily accessible 1,2,...An efficient and facile synthesis of a library of hitherto novel 1,2,3-triazolyl-N-acetyl/N-propionylpyrazoline hybrids (16 examples) in excellent yields (90%-96%) has been accomplished from easily accessible 1,2,3-triazolyl chalcone precursors.展开更多
We reported the environmental benign synthesis of chalcones,2-pyrazolines and cyclohexanones under microwave irradiation.Chalcones were obtained by the condensation of each of 2-hydroxyacetophenone derivatives with a-...We reported the environmental benign synthesis of chalcones,2-pyrazolines and cyclohexanones under microwave irradiation.Chalcones were obtained by the condensation of each of 2-hydroxyacetophenone derivatives with a-naphthaldehyde under microwave irradiation.The condensation reactions of each of synthesized chalcones with phenyl hydrazine under microwave irradiation in the presence of dry acetic acid as a cyclizing agent gave 2-pyrazolines.Also,the new cyclohexenone derivatives,valuable intermediates to synthesize fused heterocycles,have been prepared by the cyclocondensation of each of hydroxychalcones with ethyl acetoacetate.The structures of the synthesized compounds were elucidated by infrared(IR) spectrometry,nuclear magnetic resonance(NMR),mass spectrometry(MS) and elmental analysis.The results indicate that unlike classical heating,microwave irradiation results in higher yields with shorter and cleaner reactions.The synthesized compounds were screened for antimicrobial activity against Staphylococcus aureus,Escherichia coli,Candida Albicans and Aspergillus niger.We clarified the effects of different substituents in the tested compounds on the obtaind antibacterial activities and antifungal activities.展开更多
A highly enantioselective 1,3-dipolar cycloaddition ofα-substituted diazoesters with exocyclic enones was achieved with chiral scandium(III)/N,N’-dioxide complex as the catalyst.This protocol provided a facile and e...A highly enantioselective 1,3-dipolar cycloaddition ofα-substituted diazoesters with exocyclic enones was achieved with chiral scandium(III)/N,N’-dioxide complex as the catalyst.This protocol provided a facile and efficient route to optically active 1-pyrazoline-based spirochromanones and others with good outcomes(up to 97%yield,98%ee with>95:5 dr).Moreover,enantioenriched 2-pyrazoline-based spirochromanones were also accessible by switchingα-substituted diazoesters toα-diazoacetates.The further specific transformations of chiral pyrazoline-based spiro-compounds to spirocyclopropane derivatives were disclosed as well.展开更多
A novel and practical method for the synthesis of 3,5-bis(trifluoromethyl)-4,5-dihydro-1H-pyrazoles by [3+2] cycloaddition reactions of α-(trifluoromethyl)styrenes with 2,2,2-trifluorodiazoethane (CF3CHN2) has been d...A novel and practical method for the synthesis of 3,5-bis(trifluoromethyl)-4,5-dihydro-1H-pyrazoles by [3+2] cycloaddition reactions of α-(trifluoromethyl)styrenes with 2,2,2-trifluorodiazoethane (CF3CHN2) has been developed. The cyclization reaction proceeds smoothly in the presence of a catalytic amount of Et_(3)N, affording a variety of bis(trifluoromethyl)-substituted 2-pyrazolines in good to excellent yields. This method also exhibits a broad substrate scope and tolerates various functional groups.展开更多
1 Results 2-pyrazolines and carbaozole derivatives are well known fluorescent compounds with high quantum yields[1],and have been investigated in many other respects[2,3].In this paper,carbazole radical was introduced...1 Results 2-pyrazolines and carbaozole derivatives are well known fluorescent compounds with high quantum yields[1],and have been investigated in many other respects[2,3].In this paper,carbazole radical was introduced to pyrazoline ring on C-5,and a novel derivative,named 1-phenyl-3-biphenyl-5-(N-ethyl carbazole-3-yl)-2-pyrazoline (PBEP) (5) was synthesized: The product PBEP was characterized by IR,1H NMR,and elementary analysis.Yield: 47.2%.M.P 104-106 ℃.1H NMR (CDCl3) δ/10-6: 1.5(3H,—CH3).2.4(2H,—...展开更多
A novel fluorescent ionophore derived from calix[4]arene and pyrazoline was designed and synthesized.Its molecular structure was confirmed by ^1H NMR and element analysis.The resulting material shows specific fluoresc...A novel fluorescent ionophore derived from calix[4]arene and pyrazoline was designed and synthesized.Its molecular structure was confirmed by ^1H NMR and element analysis.The resulting material shows specific fluorescent behavior toward the Zn^2+ion among the other divalent metal ions,such as Co^2+,Ni^2+,Cu^2+.The primary results indicate this ionophore material is a potential material for developing efficient fluorescent Zn^2+ chemosensors.展开更多
The title compound 2-(5-(4-chlorophenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)- pyridine(C20H16ClN3, Mr = 333.81) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction...The title compound 2-(5-(4-chlorophenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)- pyridine(C20H16ClN3, Mr = 333.81) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 10.9925(12), b = 11.0378(12), c = 14.2751(18) , β = 98.074(11)°, V = 1714.9(3)3, Z = 4, Dc = 1.293 g/cm3, μ(MoKα) = 0.228 mm-1, F(000) = 696, the final R = 0.0521 and wR = 0.1349 for 3495 observed reflections with I 〉 2σ(I). Intermolecular C–H...π interactions and π-π stacking interactions stabilize the crystal structure. The binding study by fluorescence spectroscope titration showed that the title compound can selectively recognize Fe3+ in THF solution with fluorescence quenching.展开更多
A novel compound constructed from polyoxometalate (H3PW12O40,PW12) and poly(amidoamine) (PA) was prepared at room temperature in an aqueous solution by an impregnation method.A series of novel 1,3,5-triaryl-2-pyrazoli...A novel compound constructed from polyoxometalate (H3PW12O40,PW12) and poly(amidoamine) (PA) was prepared at room temperature in an aqueous solution by an impregnation method.A series of novel 1,3,5-triaryl-2-pyrazoline derivatives was synthesized by the reaction between chalcone and phenylhydrazine in the presence of the title compound,PW12/PA,in high yields.The structures of the compounds obtained were determined by IR and 1H NMR spectra.展开更多
Fluorescence properties of 1-pheny1-3-(4'-nitrophenyl) pyrazoline (PNP) were studied inbulk polymerization process of methylmethacrylate (MMA). The fluorescence intensity of PNPwas enhanced and the emission maximu...Fluorescence properties of 1-pheny1-3-(4'-nitrophenyl) pyrazoline (PNP) were studied inbulk polymerization process of methylmethacrylate (MMA). The fluorescence intensity of PNPwas enhanced and the emission maximum was blue shifted with the polymerization progress. Inthe period of auto-acceleration of the polymerization the enhancement of fluorescence intensityand blue shift of peak wavelength in spectra could be observed evidently. This means that thesolvatochromic properties of PNP are influenced not only by the solvent polarity but also by theviscosity of the medium (especially by the phase transitiott). In solid state PNP emits from thecharge transfer excited state without solvent relaxation. The transient emission spectra and theresults from Bakhshiev model of solvent relaxation coincide with that from the polymerizationexperiment.展开更多
基金supported by the Foundation of Science and Technology Bureau,Sichuan Province(No. 2006j13-141)the National Natural Science Foundation of China(No.20672076).
文摘In this paper, the synthesis and characterization of a triarylpyrazoline modified four-H-bonded molecular duplex are described. Its molecular structure has been confirmed by ^1H NMR and ESI-MS. The duplex emits strong pure blue light peaking at 448 and 452 nm under UV photoexcitation in solution and solid state, respectively, and its relative photoluminescence quantum efficiency in solution is determined as 0.778 using quinine sulfate as reference. In concentration of 〉40 mmol/L, the duplex can gelate DMSO, and the organogel formed shows good pure blue photoluminescence too. This novel duplex, for its well-defined structure and efficient photoluminescence property, is a prospective candidate for pure blue electroluminescent emitter.
文摘Nine complexes of rare earths with 5 phenyl pyrazoline dithioformate, Na[RE(S 2CNC 9H 9 N) 4· x H 2O (RE=La~Dy, Y, except for Ce and Pm) were synthesized in dry N 2 atmosphere and characterized by elemental analyses, molar conductance, IR spectra, thermal analyses. The results show that the ligands coordinate to the RE ion through two sulphur atom donors. Thermal analyses indicate that the thermal stability of the complex is not higher than that of sodium 5 phenyl pyrazoline dithioformate. The complexes are easily soluble in acetonitrile and tetrahydrofuran. The molar conductance values of the complexes measured in acetonitrile (1 24~1 32×10 -3 mol·dm -3 ) at 25 ℃ are in the range of 86~104 Ω -1 ·cm 2·mol -1 , indicating that they are 1∶1 electrolytes.
基金Supported by Anhui university scientific finance fund for distinguished young scholar (2004jq181)
文摘The molecular structures of ground state and first single excited state for pyrazoline derivatives are optimized with DFT B3LYP method and ab initio “configuration interaction with single excitations”(CIS) method, respectively. The frontier molecular orbital characteristics have been analyzed systematically, and the electronic transition mechanism has been discussed. Electronic spectra are calculated by using TD-DFT method. These results are consistent with those from the experiment.
基金The project was supported by the National Natural Science Foundation of China (20172039, 20472062) and Natural Science Foundation of Jiangsu Province (No. BK2004038)
文摘Two pyrazoline derivants 1-(2-benzothiazole)-3-phenyl-5-(3-thiophene)-2- pyrazoline (BPTP) and 1-(2-benzothiazole)-3-(2-thiophene)-5-phenyl-2-pyrazoline (BTPP) have been synthe- sized and their crystal structures were determined by X-ray single-crystal diffraction. Crystal of BPTP belongs to triclinic, space group P1 with a = 9.4430(11), b = 9.9384(13), c = 9.9394(13) ?, α = 83.107(10), β = 79.947(10), γ = 70.221(7)o, V = 862.42(19) ?3, Z = 2, Dc = 1.392 g/cm3, μ(MoKα) = 0.316 mm-1, F(000) = 376, λ = 0.71070 ?, (?ρ)max = 0.348, (?ρ)min = –0.481 e/?3, the final R = 0.0407 and wR = 0.1055 for 2844 observed reflections with I > 2σ(I). Crystal of BTPP is of monoclinic, space group P21/c with a = 11.6158(17), b = 11.2796(18), c = 13.082(2) ?, α = 90, β = 91.087(4), γ = 90o, V = 1713.7(5) ?3, Z = 4, Dc = 1.401 g/cm3, μ(MoKα) = 0.318 mm-1, Mr = 361.07, F(000) = 752, λ = 0.71070 ?, (?ρ)max = 0.322, (?ρ)min = –0.330 e/?3, the final R = 0.0563 and wR = 0.1058 for 3434 observed reflections with I > 2σ(I).
基金Project No.20572040 was supported by National Natural Science Foundation of China.
文摘1,3,5-Trisubstituted pyrazolines were oxidized to the corresponding pyrazoles in high yield with tris(4-bromophenyl)aminium (TBPA**) hexachloroantimonate in chloroform at room temperature.
文摘Three kinds of pyrazolines were designed and synthesized. Their structures were elucidated by IR, (HNMR)-H-1, MS, UV and elemental analysis. Their luminescent properties were determined, which indicated that they had strong blue fluorescent properties. One of them was designed to have good film formation. All the three kinds of pyrazolines can be used as blue organic electroluminescence materials (OELMs).
文摘Various recent reports on Tuberculosis have alarmed an increase in the patient class and subsequent death rates across the globe. Over and above the spread of more dangerous and fatal forms of tuberculosis like MDR-TB i.e. multiple-drug resistance tuberculosis, XDR-TB i.e. extensively-drug resistance tuberculosis & TDR-TB i.e. total-drug resistance tuberculosis has forwarded an urgent need to discover novel antitubercular agents. The current work is aimed at combining two previously well-known pharmacophores (pyrazoline and benzoxazole nucleus) in order to design and synthesize a series of novel benzoxazole-based pyrazoline derivatives. The synthesized target compounds were structurally confirmed by LCMS, 1H-NMR and 13C-NMR analysis. The target compounds were In vitro evaluated against M. tuberculosis H37Rv strain, multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) strains. The In vitro screening results depicted that majority of the target compounds displayed potent activity with MIC in a range of ~0.8 to 6.25 μg/mL. Many compounds were found to be more potent than isoniazid against MDR-TB with MIC value 3.12 μg/mL and XDR-TB with MIC value 12.5 μg/mL. Cytotoxicity assay of these active compounds on VERO cell lines also displayed good selectivity index.
文摘Eight new compounds containing in their structures substituted quinoline and pyrazole entity were synthesized in good to excellent yield by cyclocondensation reaction of chalcones and hydrazine hydrate. This reaction was conducted in formic acid in presence of BF3·Et2O or in acetic acid. These approaches were extended to bis-chalcones, which delivered functionalized bispyrazolines. The structures of the prepared compounds were confirmed by IR, 1HNMR, 13CNMR and mass spectral analysis.
文摘b Département de Physique, Ecole Polythechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland c Department of Chemistry, Tsinghua University, Beijing 100084, China An excellent hole-transport material, 1,3-diphenyl-5-(9-phenanthryl)-2-pyrazoline (DPPhP) for OLEDs was studied. This compound not only offers high glass transition temperature (T g=96 ℃), good film forming ability, and high HOMO energy level, but also displays excellent hole-transport property. The electroluminescent device with a simple structure of ITO/DPPhP (60 nm)/AlQ (60 nm)/LiF (0.8 nm)/Al shows an external quantum efficiency as high as 1.6%.
基金partial financial support by Guangdong Natural Science Foundation(No.7006672)South China Agricultural University Foundation(Nos.2009B010100001, 2009C020604002)
文摘A series of novel 5-phenyl-3-(2,2':5',2″-terthien-5-yl)-4,5-dihydro-lH-pyrazolines were synthesized in this report. Their photoactivated cytotoxicities on the 5podoptera litura (SL) cell line were evaluated using the MTT method. It was noticed that the inhibitory activities of all the conjugates was enhanced when irradiated with UV-A light. Compounds 4, 6 and 8 were found to be most effective with inhibition rates of 88.1%, 88.0%, and 90,5%, respectively, For compound B, the inhibition rate value was only slightly enhanced under the irradiation treatment (78.3%) compared to the dark treatment (74.8%). The relationship analysis between structure and activity showed that the middle thiophene ring played an important role on the inhibitory activities. It was shown that these compounds could be the potential candidates for new photoactivated pesticides.
基金UGC(BSR)-India for givingfinancial support as JRF&SRF
文摘An efficient and facile synthesis of a library of hitherto novel 1,2,3-triazolyl-N-acetyl/N-propionylpyrazoline hybrids (16 examples) in excellent yields (90%-96%) has been accomplished from easily accessible 1,2,3-triazolyl chalcone precursors.
文摘We reported the environmental benign synthesis of chalcones,2-pyrazolines and cyclohexanones under microwave irradiation.Chalcones were obtained by the condensation of each of 2-hydroxyacetophenone derivatives with a-naphthaldehyde under microwave irradiation.The condensation reactions of each of synthesized chalcones with phenyl hydrazine under microwave irradiation in the presence of dry acetic acid as a cyclizing agent gave 2-pyrazolines.Also,the new cyclohexenone derivatives,valuable intermediates to synthesize fused heterocycles,have been prepared by the cyclocondensation of each of hydroxychalcones with ethyl acetoacetate.The structures of the synthesized compounds were elucidated by infrared(IR) spectrometry,nuclear magnetic resonance(NMR),mass spectrometry(MS) and elmental analysis.The results indicate that unlike classical heating,microwave irradiation results in higher yields with shorter and cleaner reactions.The synthesized compounds were screened for antimicrobial activity against Staphylococcus aureus,Escherichia coli,Candida Albicans and Aspergillus niger.We clarified the effects of different substituents in the tested compounds on the obtaind antibacterial activities and antifungal activities.
基金This work was supported by the National Natural Science Foundation of China(U19A2014,21890723).
文摘A highly enantioselective 1,3-dipolar cycloaddition ofα-substituted diazoesters with exocyclic enones was achieved with chiral scandium(III)/N,N’-dioxide complex as the catalyst.This protocol provided a facile and efficient route to optically active 1-pyrazoline-based spirochromanones and others with good outcomes(up to 97%yield,98%ee with>95:5 dr).Moreover,enantioenriched 2-pyrazoline-based spirochromanones were also accessible by switchingα-substituted diazoesters toα-diazoacetates.The further specific transformations of chiral pyrazoline-based spiro-compounds to spirocyclopropane derivatives were disclosed as well.
基金support from the National Key Research and Development Program of China(No.2017YFD0200505)。
文摘A novel and practical method for the synthesis of 3,5-bis(trifluoromethyl)-4,5-dihydro-1H-pyrazoles by [3+2] cycloaddition reactions of α-(trifluoromethyl)styrenes with 2,2,2-trifluorodiazoethane (CF3CHN2) has been developed. The cyclization reaction proceeds smoothly in the presence of a catalytic amount of Et_(3)N, affording a variety of bis(trifluoromethyl)-substituted 2-pyrazolines in good to excellent yields. This method also exhibits a broad substrate scope and tolerates various functional groups.
文摘1 Results 2-pyrazolines and carbaozole derivatives are well known fluorescent compounds with high quantum yields[1],and have been investigated in many other respects[2,3].In this paper,carbazole radical was introduced to pyrazoline ring on C-5,and a novel derivative,named 1-phenyl-3-biphenyl-5-(N-ethyl carbazole-3-yl)-2-pyrazoline (PBEP) (5) was synthesized: The product PBEP was characterized by IR,1H NMR,and elementary analysis.Yield: 47.2%.M.P 104-106 ℃.1H NMR (CDCl3) δ/10-6: 1.5(3H,—CH3).2.4(2H,—...
基金supported by the National Natural Science Foundation of China(No.20802033)NaturalScience Foundation of Jiangxi Province(No.2007GZC1552)Scientific Research Foundation of NanchangHangkong University(No.EA200802012).
文摘A novel fluorescent ionophore derived from calix[4]arene and pyrazoline was designed and synthesized.Its molecular structure was confirmed by ^1H NMR and element analysis.The resulting material shows specific fluorescent behavior toward the Zn^2+ion among the other divalent metal ions,such as Co^2+,Ni^2+,Cu^2+.The primary results indicate this ionophore material is a potential material for developing efficient fluorescent Zn^2+ chemosensors.
基金supported by the Hubei Province Education Ministry Foundation of China(No.D20112507)the Science Technology Foundation for Creative Research Group of HBDE(No.T201311)
文摘The title compound 2-(5-(4-chlorophenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)- pyridine(C20H16ClN3, Mr = 333.81) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 10.9925(12), b = 11.0378(12), c = 14.2751(18) , β = 98.074(11)°, V = 1714.9(3)3, Z = 4, Dc = 1.293 g/cm3, μ(MoKα) = 0.228 mm-1, F(000) = 696, the final R = 0.0521 and wR = 0.1349 for 3495 observed reflections with I 〉 2σ(I). Intermolecular C–H...π interactions and π-π stacking interactions stabilize the crystal structure. The binding study by fluorescence spectroscope titration showed that the title compound can selectively recognize Fe3+ in THF solution with fluorescence quenching.
基金supported by the Islamic Azad University,Shahreza Branch and the Research Affairs Division Isfahan University of Technology(IUT)
文摘A novel compound constructed from polyoxometalate (H3PW12O40,PW12) and poly(amidoamine) (PA) was prepared at room temperature in an aqueous solution by an impregnation method.A series of novel 1,3,5-triaryl-2-pyrazoline derivatives was synthesized by the reaction between chalcone and phenylhydrazine in the presence of the title compound,PW12/PA,in high yields.The structures of the compounds obtained were determined by IR and 1H NMR spectra.
基金This project was supported by the National Natural Science Foundation of China
文摘Fluorescence properties of 1-pheny1-3-(4'-nitrophenyl) pyrazoline (PNP) were studied inbulk polymerization process of methylmethacrylate (MMA). The fluorescence intensity of PNPwas enhanced and the emission maximum was blue shifted with the polymerization progress. Inthe period of auto-acceleration of the polymerization the enhancement of fluorescence intensityand blue shift of peak wavelength in spectra could be observed evidently. This means that thesolvatochromic properties of PNP are influenced not only by the solvent polarity but also by theviscosity of the medium (especially by the phase transitiott). In solid state PNP emits from thecharge transfer excited state without solvent relaxation. The transient emission spectra and theresults from Bakhshiev model of solvent relaxation coincide with that from the polymerizationexperiment.