Synthesis and characterization of new thiadiazole derivatives bearing a pyrazole moiety

A series of thidiazole derivatives (4, 7) from pyrazole-3-carboxylic acid chloride (2) and pyrazole-3,4-dicarboxylic acid chloride derivatives (6) were synthesized and characterized. The structures of the new compounds were confirmed byelemental analysis, NMR (¹H and ¹³C) and IR spectra. The molecular and crystal structure of 4-benzoyl-N-[5-(methylthio)-1,3,4-thiadiazol-2-yl]-1,5-di-phenyl-1H-pyrazole-3-carboxamide(4d)was determined by single crystal X-ray diffraction method.     

Synthesis and DNA cleavage evaluation of epoxypiperidine derivatives bearing a dehydroamino acid unit

Epoxypiperidine derivatives bearing a dehydroamino acid unit were designed and synthesized as novel DNA alkylating agents based on the structure of azinomycins. A relaxation assay of plasmid DNA revealed that the epoxypiperidine derivative 3 has a DNA cleavage activity. Based on the studies, it would appear that the electron density of the amino group of epoxypiperidines plays a critically important role in the DNA cleavage.     

Reactions of aromatic and heteroaromatic compounds bearing electron-acceptor substituents

The specificity of the nitration and bromination of dimethyl(2-thienyl)sulfonium salts was studied. It was found that, in contrast to methyl 2-thienyl sulfide, which reacts to form 3- and 5-substituted derivatives, the sulfonium salts give a mixture of 4- and 5-substituted products. Total suppression of the activity of the position under the influence of the sulfonium grouping is not observed.See [1] for communication VIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 310–314, March, 1972.     

Synthesis and characterization of a novel terthiophene-based quinodimethane bearing a 3,4-ethylenedioxythiophene central unit

The synthesis and a combined spectroscopic and density functional theoretical characterization of a 3',4'-ethylenedioxy-5,5' '-bis(dicyanomethylene)-5,5' '-dihydro-2,2':5',2' '-terthiophene analogue of 7,7,8,8-tetracyanoquinodimethane (TCNQ) are presented. Electrochemical data show that this novel trimer can be both reversibly reduced and oxidized at relatively low potentials. Quantum-chemical calculations show that the compound exhibits a quinoidal structure in its ground electronic state and that a certain degree of intramolecular charge transfer takes place from the central terthienyl moiety toward both =C(CN)2 end-caps. Therefore, the amphoteric redox behavior of this novel material can be related to the coexistence of an electron-impoverished terthienyl core endowed by two electron-enriched =C(CN)2 substituents. The UV-vis spectrum is dominated by the appearance of a strong absorption near 660 nm, attributable to the highest occupied molecular orbital (HOMO) --> lowest unoccupied molecular orbital (LUMO) pi-pi electronic transition of the terthienyl spine on the basis of time-dependent density functional theory (DFT) computations. The DFT calculations performed on the minimum-energy molecular geometry about the equilibrium atomic charge distribution, topologies, and energies of the frontier orbitals around the gap and about the Raman-active vibrations associated with the strongest Raman features are also consistent with a rather effective pi-electron conjugation and the partial degree of intramolecular charge transfer mentioned above. Our study reveals this novel heteroquinoid trimer could act as a promising candidate in organic field-effect transistor (OFET) applications.     

Reactions of aromatic and heteroaromatic compounds bearing electron-acceptor substituents

Dimethyl(2-thienyl)sulfonium salts were synthesized for the first time. The corresponding triiodomercurates were obtained by the reaction of methyl 2-thienyl sulfide or its substituted derivatives with methyl iodide and mercuric iodide. Sulfonium perchlorates are formed as a result of the reaction of thiophene compounds with dimethyl sulfoxide in the presence of POCl₃ and perchloric acid. The HgI₃ ^– anion was replaced by NO₃ ^– by means of an anion-exchange resin. The methods for the dimethylation of sulfonium salts with conversion of them to the corresponding sulfides were studied; the conditions for obtaining quantitative yields from these reactions by means of an anion exchange resin in the acetate form were found.See [1] for communication VII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 165–168, February, 1972.     

Reactions of aromatic and heteroaromatic compounds bearing electron-acceptor substituents

Complexing with aluminum chloride can change the specificity of the bromination of furfural in such a way that the major product becomes 4-bromofurfural. Consequently, as in the thiophene series, reinforcement of the electron-acceptor capacity of the carbonyl group by means of the complexing deactivates the free 5 position so much that the 4 position of the furan ring becomes the most active.See [1] for communication X.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 597–600, May, 1972.     

去氢枞醇杂环类化合物的合成及细胞毒性研究

以去氢枞酸(1)为原料,经氢化铝锂还原得到去氢枞醇(2),2与氯乙酰氯在氮气保护和DMAP催化条件下反应合成中间产物去氢枞醇氯乙酸酯(3),3与杂环化合物经亲核取代反应合成了12个新型去氢枞醇杂环类化合物(4a ～41).利用IR、1H NMR、13C NMR和HR-MS等对目标化合物的结构进行表征,采用MTT法测试目...     

Synthesis and characterization of some novel 1,3-diaryl pyrazole bearing 2-oxopyridine-3,5-dicarbonitrile derivatives

Russian Journal of General Chemistry - A series of new 1-{[1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazol-4-yl]methyleneamino}-6-amino-1,2-dihydro-4-(substitutedphenyl)-2-oxopyridine-3,5-di...     

含1,3,4-噻二唑环的联苯四唑衍生物的合成

通过5-芳基-2-巯基-1,3,4-噻二唑(1a～1d)与2-氰基-4'-溴甲基联苯(2)在氢氧化钾/N,N-二甲基甲酰胺体系中进行亲核取代反应,制得新化合物3a～3d,后者与(n-Bu) 3 SnCl/NaN3发生1,3-偶极环加成反应得到三甲基硒取代的四唑,再经相应后处理得四个新的含1,3,4-噻二哇类联苯四唑衍生...     

Synthesis and characterization of captopril derivatives

To develop more potential angiotensin converting enzyme (ACE) inhibitors, a series of captopril (Cap) derivatives were synthesized, including Cap-glycine methyl ester, Cap-l-alanine methyl ester, Cap-l-aspartic acid dimethyl ester, Cap-l-lysine methyl ester, Cap-O-acylisourea, acetyl captopril, and benzoyl captopril. The resulting products were characterized by IR and UV–visible spectroscopy and MS, which showed the desired products were successfully synthesized. This could serve as a guide for rational design of highly potent ACE inhibitors.     

Synthesis of an optically active electron-acceptor tetracyanoanthraquinodimethane (TCAQ) main-chain polyester

The first main-chain copolymer containing TCAQ and enantiomerically pure binaphthyl moieties connected at 2,6 positions of the TCAQ ring was successfully synthesized by means of a polycondensation reaction. Cyclic voltammetry investigations show that TCAQ preserves its acceptor ability in the polymer system and preliminary photophysical investigations show fluorescence quenching in mixtures containing the acceptor polymer and fluorescent conjugated polymers.     

Synthesis and oxidation of triarylamine derivatives bearing hydrogen-bonding groups

Hydrogen-bonding triarylamines, 4-(N,N-bis(4-methoxyphenyl)amino)benzoic acid (TPA1), 5-(N,N-bis(4-methoxyphenyl)amino)isophthalic acid (TPA2), and N-(4-(1H-benzimidazol-2-yl)phenyl)-N,N-bis(4-methoxyphenyl)amine (BImTPA), were synthesized as radical cation precursors. TPA1 and TPA2 are readily p-doped by AgSbF(6) to give highly persistent radical cations. Poor solid-state spin yields of the radical cation from BImTPA may be due to spin delocalization.     

Synthesis of cyclic boryloxyalkylphosphines with electron-acceptor substituents

Conclusions The reaction of hydroxyalkylphosphines containing electron-acceptor substituents with esters and anhydrides of boric acids and boric acid itself results in the formation of substituted 1,3-dioxa-5-phospha-2-boran-2-yl oxides.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1102–1106, May, 1985.     

Synthesis, photophysical and electroluminescent properties of novel naphthalimide derivatives containing an electron-transporting unit

A series of naphthalimide derivatives containing a benzoazole unit (benzothiazole, benzoxazole or benzimidazole) as electron-transporting unit was designed and synthesized, and their photophysical and electroluminescent properties were investigated. The key design of molecular structures included the use of carrier-transporting fragments, together with twisted molecular conformation that could eliminate the recrystallization tendency and favour the formation of a stable amorphous state. ITO/NPB/emissive layer/Mg∶Ag/Ag bilayer electroluminescent devices were fabricated. Green or yellow-green electroluminescence was obtained successfully with peak emission in the range 530–560 nm.     

Synthesis and antiviral activities of novel 1,4-pentadien-3-one derivatives bearing an emodin moiety

A series of 1,5-diaryl-1,4-pentadien-3-one derivatives bearing an emodin group were designed and synthesized by the combination of natural products. The antiviral activities against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) in vivo were evaluated. Some of the derivatives displayed promising curative effect and protective activity against TMV. Compound D5 showed appreciable curative bioactivity on TMV approximately of 50% at 306.2 mg/mL, which was superior to ningnanmycin (409.3 mg/mL).     

Synthesis and characterization of new hexahelicene derivatives

The synthesis and structural characterization of a new hexahelicene derivative 2 is reported. This compound features a new type of structure bearing a bromine atom and a methoxy group. Suitable crystals of the latter indicate that its conformation closely resembles that of the unsubstituted [6]helicene, whose idealized symmetry is C2. This 3-bromo-14-methoxyhexahelicene was subjected to lithiation/phosphinilation and yielded the new 3-methoxy-14-(diphenylphosphino)hexahelicene 3.     

Synthesis and characterization of novel spirooxazacamphorsultam derivatives

Derivatives of camphorsultam which contain novel spirooxazolidine and spirooxazine structures have been prepared in high yield and purity. Though it was expected that the ketone moiety would undergo acetal formation, the imine instead underwent reaction and was proven by X-ray crystallography and 2D NMR techniques. The initial ketone-containing derivatives were then reduced to produce exo-hydroxy analogs that have potential as a new family of chiral auxiliaries.     

Synthesis and characterization of novel second-order NLO-chromophores bearing pyrrole as an electron donor group

Two series of novel push–pull 1-(4-(thiophen-2-yl)phenyl)-1H-pyrroles 3–5 were designed to explore the consequence of using different electron accepting moieties linked to the thiophene at the arylthiophene bridge or to the pyrrole heterocycle, which plays the role of donor group. Compound 2 showed a different reactivity behavior in the presence of the Vilsmeier reagent or with tetracyanoethylene (TCNE) giving compounds 4a and 4b functionalized, respectively, at the 2 or on the 3-position of the pyrrole heterocycle. Their optical (linear and first hyperpolarizability), electrochemical, and thermal properties have been examined. Hyper-Rayleigh scattering (HRS) in dioxane solutions using a fundamental wavelength of 1064 nm was employed to evaluate their second-order nonlinear optical properties. Of these systems, thiobarbituric acid derivative 5b functionalized in the thiophene ring exhibits the largest first hyperpolarizability (β=2480×10^?30 esu, T convention) compared to the corresponding compound 4c substituted on the pyrrole heterocycle (β=290×10^?30 esu, T convention). Good to excellent thermal stabilities were also obtained for push–pull compounds 4 and 5 (270–288 °C). This multidisciplinary study shows that modulation of the optical and electronic properties can be achieved by introduction of the acceptor groups in the thiophene of the arylthiophene bridge. The measured molecular first hyperpolarizabilities and the observed electrochemical behavior are quite sensitive to the position of acceptor group on the heterocyclic system (on the thiophene or on the pyrrole ring) as well as the strength of the acceptor moieties. Moreover, the combination of their good nonlinearity and high thermal stability make them good candidates for second-order nonlinear optical applications.