bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time‐Resolved High and Low Temperature Phase Transitions of the Nanocrystalline Cubic Phase in the Y2O3‐ZrO2 and Fe2O3‐ZrO2 System
Authors: Lajavardi Manouchehr , Kenney Donald J. , Lin Sheng Hsien 
Published: May 2015

AbstractThe nanocrystalline cubic Phase of zirconia was found to be thermally stabilized by the addition of 2.56 to 17.65 mol % Y2O3 (5.0 to 30.0 mol % Y, 95.0 to 70.0 mol % Zr cation content). The cubic phase of yttria stabilized zirconia was prepared by thermal decomposition of the hydroxides at 400°C for 1 hr. 2.56 mol % Y2O3‐ZrO2 was stable up to 800°C in an argon atmosphere. The samples with 4.17 to 17.65 mol % Y2O3 were stable to 1200°C and higher. All samples at temperatures between 1450°C to 1700°C were cubic except the sample with 2.56 mol % Y2O3 which was tetragonal. The crystallite sizes observed for the cubic phase ranged from 50 to 150 Å at temperatures below 900°C and varied from 600 to 800 nm between 1450°C and 1700°C. Control of furnace atmosphere is the main factor for obtaining the cubic phase of Y‐SZ at higher temperature.Nanocrystalline cubic Fe‐SZ (Iron Stabilized Zirconia) with crystallite sizes from 70 to 137 Å was also prepared at 400°C. It transformed isothermally at temperatures above 800°C to the tetragonal Fe‐SZ and ultimately to the monoclinic phase at 900°C. The addition of up to 30 mol % Fe(III) thermally stabilized the cubic phase above 800°C in argon. Higher mol % resulted in a separation of Fe2O3. The nanocrystalline cubic Fe‐SZ containing a minimum 20 mol % Fe (III) was found to have the greatest thermal stability. The particle size was a primary factor in determining cubic or tetragonal formation. The oxidation state of Fe in zirconia remained Fe3+. Fe‐SZ lattice parameters and rate of particle growth were observed to decrease with higher iron content. The thermal stability of Fe‐SZ is comparable with that of Ca‐SZ, Mg‐SZ and Mn‐SZ prepared by this method.
Preparation of Thaliporphine and Lirioferine from Glaucine by Treatment with Hydrogen Bromide
Authors: Rao N. S. Kameswara , Lee Shoei‐Sheng 
Published: May 2015

AbstractGlaucine (2), an aporphine alkaloid, when treated with HBr gas in dichloromethane for five days at room temperature afforded thaliporphine (1), a potent cardiotonic agent, lirioferine (7), N‐methyllaurotetanine (8) and bracteoline (9), in 20%, 10%, 4% and 7% yields, respectively. The same products were obtained in the yields of 26% (1), 15% (7), 10% (8) and 12% (9) when glaucine was refluxed with acetic acid saturated with HBr gas for one hour. This study provides an alternative method to prepare thaliporphine and is the first semisynthesis for lirioferine.
Synthesis of N‐(1‐oxyl‐2,2,5,5‐tetramethylpyrrolin‐3‐yl)‐N′‐(3‐aryl‐5‐mercapto‐1,2,4‐triazol‐4‐yl)ureas and N‐(3‐aryl‐5‐mercapto‐1,2,4‐triazol‐4‐yl)‐(1‐oxyl‐2,2,5,5‐tetramethylpyrrolin‐3‐yl)acidamide
Authors: Zhang Yan , Sun Xiao‐Wen , Zhang Zi‐Yi , Wang Qin , Wang Shu‐Fang 
Published: May 2015

AbstractNine novel N‐(1‐oxyl‐2,2,5,5‐tetramethylpyrrolin‐3‐yl)‐N′‐(3‐aryl‐5‐mercapto‐1,2,4‐triazol‐4‐yl)ureas 3a∼3i were synthesized by the reaction of 1‐oxyl‐2,2,5,5‐tetramethylpyrrolin‐3‐yl isocyanate 1 with 4‐amino‐3‐aryl‐5‐mercapto‐1,2,4‐triazoles 2a∼2i and their anti‐tumor activity was evaluated. The mass spectra of the compounds synthesized were discussed.
Synthetic Studies of a Didemnin B Analog Based on a 2,3‐Diamino Sugar Scaffolding
Authors: Ramanjulu Joshi M. , Joullié Madeleine M. , Li Wen‐Ren 
Published: May 2015

AbstractReductive amination, amide formation using BOP [(1H‐1,2,3‐benzotriazol‐1‐yloxy)tris(dimethylamino)‐phosphonium hexafluorophosphate] and esterification via DCC (dicyclohexylcarbodiimide) were the key synthetic steps to generate an advanced intermediate in the preparation of a didemnin B analog based on a sugar scaffolding (2). This analog should provide insight into the bioactive conformation of didemnin B.
Synthesis and Biological Activity of Some New Diaryl Sulphones Containing Fused Thiazolo Pyrimidines
Authors: Kandeel Maymona M. 
Published: May 2015

AbstractThis paper describes the synthesis of some pyrimido[2,1‐b]benzothiazol‐8‐yl sulphones (7, 9, 11, 13, 14, 16) starting from bis[2‐aminobenzothiazol‐6‐yl)sulphone 1. Reaction of 1 with acetic anhydride and/or benzoyl chloride gave substituted amino derivatives 2a,b, whereas its reaction with phenacyl bromide and/or p‐chlorophenacyl bromide gave imidazo benzothiazol‐7‐yl sulphones 4a,b.
A Novel MHDV Descriptor for Dipeptide QSAR Studies
Authors: Liu Shushen , Yin Chunsheng , Cai Shaoxi , Li Zhiliang 
Published: May 2015

AbstractA novel molecular holographic distance vector (MHDV) is proposed to characterize the structures of the peptide molecules and employed to relate to the biological activities of the peptides by means of principal component regression (PCR) method. For two pan els of dipeptides, the correlation coefficient (R) between the estimated and the observed activities are respectively 0.9370 and 0.9585 and the R obtained by cross‐validation method are respectively 0.8676 and 0.9295, which is the best result to date for the two sets of dipeptides. The novel MHDV descriptor only depends on distance matrix and various atomic types of non‐hydrogen atoms in a molecule and requires no 3D structural information, so, it is a very simple and easy to use descriptor.
Asymmetry and Spin Polarization Parameters of Photoelectrons from the Zn Atom
Authors: Wang Lin‐Ru , Huang Keh‐Ning 
Published: May 2015

AbstractAsymmetric and spin polarization parameters of photoelectrons from the neutral zin atom are obtained by using the relativistic random‐phase approximation (RRPA). These parameters in the energy range near the first ionization thresh old are very sensitive to valence‐core correlations. The present results are in good agreement with recent measurements.
Cylindrical and Spherical Microcavity Lasers Based on Evanes Cent‐Wave‐Coupled Gain
Authors: An Kyungwon 
Published: May 2015

AbstractWe report operation of microcavity lasers based on the gain only in the evanes cent field region of whispering gallery modes. Two types of microcavities, microsphere and microcylinder, were used. First a cylindrical microcavity of 125 micron in diameter was surrounded by Rhodamine 6G dye molecules in ethanol solution of lower refractive index such that WGM's of the microcavity undergo laser oscillation when the dye molecules in the evanescent field region out side the cavity are excited by a second harmonic of a Nd: YAG laser. In the second experiment an ultrahigh Q microsphere was used for a cavity. The dye molecules out side the sphere, near the equator, of 102 μm diameter were excited, resulting in WGM lasing in the lowest radial mode order. The loaded quality factors of the cavity in this case were found to exceed 2 × 109, which would be high enough to support lasing with only a single quantum radiator coupled to the WGM.
Fine‐structure in 3d4 States of Highly Charged Ti‐like Ions
Authors: Kato Daiji , Tong Xiao‐Min , Watanabe Hirofumi , Fukami Tsunemitsu , Kinugawa Tohru , Yamada Chikashi , Ohtani Shunsuke , Watanabe Tsutomu 
Published: May 2015

AbstractA remarkable improvement of ab initio calculations was obtained for wavelengths of (3d4) J = 3 → 2 forbid den transition. Present calculations reduced the long‐standing discrepancy from measurements down to less than 0.2% for most high‐Z titanium‐like ions. In the present calculations, a large extent of configuration space was included so that most important many‐body effects were taken into account. To this end, the linearized second‐order Brillouin‐Wigner perturbation theory was employed with optimized spin‐orbitals. Transition probability and atomic g‐factor were also calculated with the improved atomic wave functions.
Magnetic Guide and Trap for Cold Neutral Atoms with Current‐Carrying Wires and Conductors
Authors: Yin Jianping , Gao Weijian , Liu Nanchun , Hu Jianjun , Wang Yuzhu 
Published: May 2015

AbstractWe propose two novel schemes for guiding cold, neutral atoms using static magnetic fields generated by several cylindrical arrays of current‐carrying wires or a few different‐shaped (V‐, or U‐shaped, etc.) current‐carrying conductors, and calculate the corresponding magnetic‐field contours and their trapping potentials. Our study shows that some guiding schemes can be used to form an atomic funnel, or an atomic beam‐splitter, or even construct an atomic interferometer, and some guiding schemes can be used to realize a single‐mode wave guide of ultracold atoms (or coherent matter waves, BEC) under certain conditions. We also propose a few new schemes to microscopically trap neutral atoms by using various planar arrays of current‐carrying wires and calculate the spatial distribution of the magnetic fields. Our research shows that these microtrap arrays can be used to form 1D, 2D or 3D atomic magnetic lattices, and then to prepare 1D, 2D or 3D photonic crystals, even to realize a 1D, 2D or 3D array of magnetically‐trapped BECs or Bose Clusters.
Quantum Effects in Potential‐Well Scattering
Authors: Cheng Wen‐Yu , Huang Keh‐Ning 
Published: May 2015

AbstractParticle scattering through a spherical potential well is treated by three successive procedures to demonstrate the quantum effects. The differential cross section from a geometric treatment as in geometric optics consists of an incoherent sum of components associated with each geometric path, while the geometric‐phase treatment gives rise to the coherence among components. By considering Huygens' principle, the wave treatment as in wave optics brings an additional term to the differential cross section, which corresponds to the Fraunhofer diffraction in optics.
Kinetics and Mechanism of Dehydrochlorination of 3‐Chloro‐1,5‐diarylformazans and Their Mass Spectra
Authors: Shawali Ahmad S. , Abdelkhalek Ahmad A. , Sayed Abdelwahed R. 
Published: May 2015

AbstractIn aqueous dioxane containing triethylamine the title 3‐chloroformazans 1 are converted into the corresponding 1,4‐bis(arylazo)‐3,6‐diaryl‐1,2,4,5‐tetrazines 3 via head‐to‐tail dimerization of the intitially formed 1,3‐dipolar ions 2. The kinetics of triethylamine‐catalyzed dehydrochlorination of 1 in 70% dioxane at 27°C and ionic strength of 0.1 were studied. The rate data were linearly correlated with enhanced Hammett substituent constants σx− and an overall ρ value of 0.2 was determined for the variation of the N‐aryl substituent. These results were interpreted in terms of a two‐step mechanism. Also, the mechanisms of the unimolecular fragmentation of 1 and 3 in the mass spectrometer are discussed.
Structure and Magnetic Property of a Novel Nitronyl Nitroxide Biradical
Authors: Zhao Qi‐Hua , Jiang Zong‐Hui , Liao Dai‐Zheng , Yan Shi‐Ping , Fang Rui‐Bin 
Published: May 2015

AbstractA new biradical of nitronyl nitroxide, 1,3‐[di‐2‐(4,4,5,5‐tetramethyl‐4,5‐dihydro‐1H‐imidazolyl‐1‐oxyl‐3‐oxide) phenoxy]propane [BNITPhOPr (1)], was prepared and characterized. The temperature dependence of the magnetic susceptibility values were observed for 1 in the range of 2–300 K. The observed data was successfully simulated giving the exchange integral J = −0.47 cm−1, θ = −0.94 K. This result indicates a weak antiferromagnetic spin exchange interaction between the biradicals.
Synthesis and Biological Activity of New Selected Different Heterocyclic Nitrogen Compounds Incorporating 1,4‐naphthquinone
Authors: Khalafallah Ali Kamel 
Published: May 2015

AbstractCondensation of 1‐phenylnaphthcyclopentan‐2,4,9‐trione (II) with aromatic aldehydes yielded the corresponding 3‐benzylidene deivatives (IIIa‐f). Interaction of IIIa‐f with hydrazines, hydroxylamine, urea and thiourea afforded some new (pyrazoline IVa‐f, Va‐f, Isoxazolino VIa‐f pyrimidinone and/or pyrimidinethione, VIIa‐f, VIIIa‐f) derivatives, respectively. Also, a series of some spirocompounds covering β‐lactams and thiazolidinones (Xg‐j, XIg‐j) incorporating 1‐phenylnaphthcyclopentan‐2,4,9‐trione were prepared.
Ceramides from the Taiwan Red Alga Ceratodictyon Spongiosum and Symbiotic Sponge Sigmadocia Symbiotica
Authors: Lo Jir‐Mehng , Wang Wei‐Lung , Chiang Young‐Meng , Chen Chiu‐Ming 
Published: May 2015

AbstractThe structure of a mixture of ceramides (1) de rived from 2‐amino‐4(E)‐alkene‐1,3‐diol sphingenines with C22, C23, and C24 saturated fatty acid residues from red alga Ceratodictyon spongiosum ZANARDINI (Rhodymeniaceae) containing the symbiotic sponge Sigmadocia symbiotica has been elucidated on the basis of spectroscopic and chemical evidence. In addition, one new sterol, n‐nonadecanoic acid 24‐ methylenecholesteryl ester (2), and six known sterols were also isolated from the marine organisms.
Reaction of (η5‐C5H5)Fe(CO)2I with Anionic Bidentate Phosphine Ligands PPh2(o‐C6H4NHLi) or PPh2(o‐C6H4OLi)
Authors: Peng James , Wen Yuh‐Sheng , Liu Ling‐Kang 
Published: May 2015

AbstractThe o‐substituted hybrid phenylphosphines, PPh2(o‐C6H4NH2) and PPh2(o‐C6H4OH), could be deprotonated with LDA or n‐BuLi to yield PPh2(o‐C6H4NHLi) and PPh2(o‐C6H4OLi), respectively. When added to a solution of (η5‐C5H5)Fe(CO)2I at room temperature, these two lithiated reagents produce a chelated neutral complex 1 (η5‐C5H5)Fe(CO)[C(O)NH(o‐C6H4)PPh2‐C,P‐η2] for the former and mainly a zwitterionic complex 2, (η5‐C5H5)Fe+(CO)2[PPh2(o‐C6H4O−)] for the latter. Complex 1 could easily be protonated and then decarbonylated to give 4 [(η5‐C5H5)Fe(CO){NH2(o‐C6H4)PPh2‐N,P‐η2}+]. Complexes 1 and 4‐I have been crystallographically characterized with X‐ray diffraction.
Reduction of Ethyl t‐Cinnamates by Samarium Diiodide
Authors: Lin Tzuen‐Yeuan , Fuh Ming‐Ren , Chan I‐San 
Published: May 2015

AbstractRate constants directly measured from the GC‐analyzed method for SmI2 reduction of ethyl t‐cinnamate and its substituted derivatives in the presence of HMPA and t‐butanol were obtained. HMPA exhibits a stronger catalytic effect than t‐butanol. Dependence of reaction rates on concentration of SmI2 and temperature were studied. Electron‐donating groups retard this reduction; the electron‐withdrawing groups, on the other hand, enhance the reaction rates dramatically.
Simple Protocol for Synthesis and Cleavage of Tetrahydropyranyl Ethers Using FeSO4 as an Inexpensive Catalyst
Authors: Bandgar Babasaheb P. , Kasture Suhas P. 
Published: May 2015

AbstractProtection and deprotection of alcohols and phenols as tetrahydropyranyl ethers (THP ethers) using an hydrous FeSO4 under microwave irradiation without solvent is carried out.
Facile Synthesis and Biological Evaluation of Some Heterocyclic Systems Containing Diazepam
Authors: Berghot M. A. 
Published: May 2015

AbstractOxadiazoles 4, 5, 6, 12, 14 and 22 were prepared binary attached with Diazepam (1). Thiadiazoles 15, 20 and Triazoles 7, 8, 9, 17, 18, 19 and 21 were also prepared. The structures of hitherto unknown compounds were confirmed by analytical and spectral methods. Some of the synthesized compounds were screened to test their antibacterial activity.
Preparation of Hydroquinone‐Containing Polymers by ROMP
Authors: Chow Tahsin J. , Yang Ya‐Chen , Chiu Nan‐Yun , Hsu Ming‐Ann 
Published: May 2015

AbstractPolymers containingortho‐ andpara‐hydroquinone moieties5a,band6aare prepared in good yields by ROMP from hydroquinone‐fused norbornadiene derivatives1a,band2a. Oxidation of5byielded a quinone derivative7, which is evidenced by a strong absorption at 1656 cm−1in infrared spectrum.
Dynamics and Orientation Ordering of Water in Lyotropic Liquid Crystals Using 2H Double Quantum Filtered NMR Spectral Analysis
Authors: Cheng Chi‐Yuan , Hwang Lian‐Pin 
Published: May 2015

AbstractThe alignment of lyotropic liquid crystals in a magnetic field has been studied by line shape analysis of the T1 process and 2D 2H double quantum filtered (DQF) NMR to investigate water dynamics and orientational feature in Cetyltrimethylammonium bromide (CTAB)/Sodium Salicylate (NaSal)/D2O liquid crystals. The same system but in powder form was also examined. In the ordered liquid‐crystalline phase, the single quantum line shapes showed splitting of doublets due to the residual quadrupolar interaction, while the double quantum spectra observed splitting patterns with damped oscillation. The modified cone model is invoked to describe the restricted motions of bound D2O molecules. Ten to thirteen bound water molecules are found to associate with each CTAB molecule and the correlation time of wobbling motion of the bound water is in the time scale of 10−8 s. At 10°C, the motional correlation times of water in the powder sample have the same magnitude as those in the oriented sample. This study shows that the analysis of DQF relaxation spectra provides a more detailed source of motional information than the normally used measurements.
Room Temperature Phosphorescence of Aromatic Hydrocarbons in SDS Rodlike Micelles
Authors: Huang Jen‐How , Lin Wann‐Yin 
Published: May 2015

AbstractRoom temperature phosphorescence (RTP) of aromatic hydrocarbons has been investigated in deoxgenated SDS micelles and in the presence of a hydrophobic heavy‐atom containing species. No RTP was observed in spherical or sub‐rodlike micelles. In the presence of a heavy‐atom containing species, a tremendous increase in phosphorescence intensity was observed during the sphere‐to‐rod transition induced by the addition of a strong electrolyte. The increased microviscosity and the incorporation of more heavy atoms during the micellar elongation will lead to an increase in the rate of intersystem crossing and a decrease in the rates of nonradiative processes, favoring the observation of RTP. At high temperatures, the phosphorescence intensity is reduced dramatically probably because of the decrease in rigidity and aggregation number of the micelle with less heavy atoms incorporated. Various heavy‐atom containing species induce RTP to a different extent. Iodoethane exhibits the most prominent heavy atom effect. 1,2‐Dibromoethane, 1‐bromopropane, and bromobenzene are about 40% as efficient as iodoethane in inducing RTP, while long‐chain 1‐bromoalkanes and polar species are much less efficient. This study demonstrates the feasibility of detecting RTP in deoxygenated SDS rodlike micelles using a suitable hydrophobic heavy‐atom containing species.
Synthesis of Symmetric and Unsymmetric 1,1′‐Dialkenylferrocenes via Samarium Diiodide Promoted Reactions of 1,1′‐Diacetylferrocene with Halides
Authors: Jong Shean‐Jeng , Fang Jim‐Mm , Liu Yi‐Hung , Wang Y. 
Published: May 2015

AbstractMonoalkenylferrocenes were prepared from 1,1′‐diacetylferrocene and appropriate benzyl bromides by the promotion of samarium diiodide. A practical method for preparation of both symmetric and unsymmetric dialkenylferrocenes was also explored. The reactions were stereoselective to give only (E) double bonds. The unsymmetric dialkenylferrocene bearing electron‐donating substituent (e.g. methoxy group) and electron‐withdrawing substituent (e.g. cyano group) on different phenyl rings likely exhibits a large nonlinear optical property.
Spectrophotometric and Polarographic Studies on the Kinetics of Hydrolysis of N‐(6‐Methyl‐5‐Nitropyridin‐2‐yl Methylidene)‐N′‐(Substituted Thiazol‐2‐yl)Hydrazines
Authors: El‐Nady Abobakr M. 
Published: May 2015

AbstractThe kinetics of the hydrolysis of hydrazone de rived from nitropyridine 2‐carboxaldehyde and 2‐hydrazino‐4‐substituted thiazoles Ia‐e in 10% (v/v) DMF‐buffer mixture has been investigated by applying two in dependent and different techniques viz UV‐spectrophotometry and differential pulse, polarography (DPP). The hydrolysis has been found to follow general acid‐base catalysis. Mechanism for the hydrolysis in acidic medium has been postulated. The observed rate constants, activation and thermodynamic parameters for the hydrolysis have been calculated. The effects of pH, molecular structure, temperature and change in percent age of water in the DMF‐buffer mixture on the rate of hydrolysis have been discussed.
Thermodynamic Study of the Ion‐Pairing of Some Transition Metal Perchlorates in Urea‐Water Mixtures from Conductivity Measurements
Authors: Bakr Moustafa Farag 
Published: May 2015

AbstractThe conductivity of some transition metal perchlorates, M(ClO4)2 (M2+ = Mn, Co, Ni, Cu and Zn) has been measured in urea‐water mixtures at 288–318 K. The limiting molar conductivities and the ion association constants of these electrolytes were calculated by the Shedlovsky extrapolation method. The ion association constants de creased in the order Co > Ni > Zn with increasing the atomic number, whereas Cu > Mn in the ionic association constants as are suit of the maximum temperature dependencies of Cu2+.The thermodynamic functions, ΔH° and A S°, for the formation of that ion pair have also been obtained.Both ΔH° and ΔS° for all the salts under study are positive values. On the other hand, the Walden products, Δoη, of the salts in crease with an in crease in temperature at 288–318 K, which indicate that these electrolytes be have as structure‐makers or promotors. Also, the activation energies, E, have been calculated and discussed.
Extraction of Palladium(II) with Cyanex‐923 and Cyanex‐471X from Bromide Media and its Separation from Pt(IV), Rh(III) and Ir(III)
Authors: Duche Sharad N. , Dhadke Purashottam M. 
Published: May 2015

AbstractThe distribution equilibria of Pd(II) between aqueous bromide media and Cyanex‐923 as well as Cyanex‐ 471X in toluene was studied as a function of the concentration of extractants and the acid concentration. The extraction behaviour of Cyanex‐471X is compared with Cyanex‐923 as they contain different donor atoms. The quantitative extraction of Pd(II) was observed with Cyanex‐923 in toluene from 4.0–8.0 mol l−1 HBr media and was stripped out with 2.0 mol l−1 hydrochloric acid. Similarly Pd(II) was quantitatively extracted with Cyanex‐471X in toluene from 6.0–8.0 mol l−1 HBr media and was stripped out with 7.0 mol l−1 NH3 solution as well as 1.0 mol l−1 of stabilized sodium thiosulfate solution at pH 4.4. The stoichiometry of the Cyanex‐923 and Cyanex‐471X extracted species determined from slope analysis was 1:2 and 1:1, respectively. Palladium(II) was extracted and separated from its binary and ternary mixture.These methods were successfully employed for analysis of palladium in real samples.
Synthesis of 2,6‐Dioxatetracyclo[6.3.0.01,10.07,8]undecane and 2,7,12‐Trioxatetracyclo[6.3.1.04,11.05,9]dodecane
Authors: Chang Meng‐Yang , Chen Shui‐Tein , Chang Nein‐Chen 
Published: May 2015

AbstractThe oxa‐cage compounds 1 and 2 are synthesized from the alcohol 3 by a series of functional trans formations. Syntheses of novel skeletons 6 and 8 are also de scribed.
Synthesis and Mesomorphic Properties of Mesogens Containing Tetrafluorobiphenyl Carboxylate Groups
Authors: Chen Xi‐Mm , Wang Kan , Li Heng‐Feng , Liu Ke‐Gang , Wen Jian‐Xun 
Published: May 2015

AbstractSix series of 4–4′‐n‐alkoxy‐2′,3′,5′,6′‐tetrafluorobiphenyl carboxylate esters have been synthesized. Their mesomorphic properties were investigated and measured by optical polarizing microscopy and DSC. The results show that tar get compounds bearing a nitro group as terminal group exhibit wide mesophases. However, their terminal groups are trifluoromethyl, fluorine atoms, chlorine atoms, bromine atoms and hydrogen atoms, which aren't mesogens.
Synthesis of New Pyrazolo[3,4‐b]quinolines, Thieno[2,3‐b]quinolines and Related Condensed Heterocyclic Systems
Authors: Bakhite Etify Abdel‐Ghafar 
Published: May 2015

Abstract3‐Amino‐1H‐pyrazolo[3,4‐b]quinoline (2) was reacted with benzaldehyde, acetylacetone, ethylacetoacetate and/or phenyl isothiocyanate to give compounds 3,4,5 and 6, respectively. The interaction of 6 with some α‐haloesters and/or α‐haloketones produced the corresponding thiazolidinones 7a‐c and thiazolines 9a‐d. 1H‐Pyrazolo[3,4‐b]quinoline‐3‐diazonium chloride (11) was coupled with some active methylene compounds to give the corresponding hydrazono compounds 12a,b and 13 which, in turn were cyclized into the corresponding triazinopyrazoloquinolines 14a,b and 15 by heating in acetic acid. 3‐Aminothieno[2,3‐b] quinoline‐2‐carbohydrazide (19) and 3‐amino‐2‐(1H‐benzimidazol‐2‐yl)thieno[2,3‐b]quinoline (21) were prepared and employed as key intermediates for synthesizing the second class of the title compounds.