Synthesis of procaterol derivative having a piperidylmethanol group and its beta-adrenoceptor stimulant activities

A procaterol derivative (6) having a piperidylmethanol group was synthesized by the nucleophilic reaction of a 5-formylcarbostyril derivative with pyridyllithium, followed by selective catalytic reductions to afford the erythro-isomer. Compound 6 showed non-selective beta-adrenoceptor agonist activities like those of l-isoproterenol in an in vivo assay using anesthetized dogs.     

Synthesis and thermal properties of liquid-crystalline polyacrylates containing a carbazolyl group in the mesogen

The new acrylate monomers 4-(ω-acryloyloxyalkyloxy)-N-(9-methyl-2-carbazolylmethylene) anilines containing from 2 to 11 methylenic units in their alkyl group and a carbazolyl group in the mesogenic unit were synthesized and polymerized by azobisisobutyronitrile (AIBN) as radical initiator and by low-energy electron beam (EB) initiation. The thermal properties of the resulting polymers were examined using differential scanning calorimetry and thermal optical polarizing microscopy. The polymer prepared by AIBN with a hexamethylene spacer exhibited a nematic phase from 73 to 170°C and with an undecamethylene spacer exhibited a smectic phase from 55 to 202°C. The isotropization temperature of the polyacrylates increased with increasing the number of carbons of the methylenic spacer. The yield of the resulting polymer was changed by EB irradiation temperature from 4.5 to 41%. The highest yield was obtained when the monomer was polymerized in a liquid-crystalline phase. The same tendency was observed in the molecular weight of the resulting polymers. © 1994 John Wiley & Sons, Inc.     

Competitive formation of cis and trans derivatives in the nucleophilic substitution reactions of cyclophosphazenes having a mono-spiro P-NHR group

Nucleophilic substitution reactions of N(3)P(3)Cl(4)[NH(CH(2))(3)NMe] (1) and N(3)P(3)Cl(4)[NH(CH(2))(3)O] (2) with mono-functional alcohols (methanol, 2,2,2-trifluoroethanol, phenol) and a secondary amine (pyrrolidine) were used to investigate the relationship between the incoming nucleophile and the proportions of products with substituents that are cis or trans to the spiro NH moiety. The reaction products were characterized by elemental analysis, mass spectrometry, (1)H and (31)P NMR spectroscopy and the configurational isomers by X-ray crystallography. Six products have been characterised with the substituent cis to the spiro NH group for the alcohol (methanol, phenol) and pyrrolidine derivatives of both compounds 1 and 2, compared to just one derivative with the substituent trans to the spiro NH group, that for the pyrrolidine derivative of compound 2. For each reaction the relative proportions of cis and trans isomers were determined by (31)P NMR measurements of the reaction mixtures. It was found that the reactions of compound 1 with all three alcohols and of compound 2 with methanol lead to exclusive formation of isomers with the substituent cis to the NH moiety, whereas all other reactions lead to mixtures of cis and trans isomers in different ratios under standard reaction conditions. However, when crown ether is included in the reaction medium for the reactions of compound 2 with both 2,2,2-trifluoroethanol and phenol, it is found that only cis isomers are formed. All these results are rationalised in terms of the competition between at least two effects; the cis-directing effect by hydrogen bonding of the incoming nucleophile to the spiro N-H group already present on the cyclophophazene ring and the cis-directing effect of the sodium cation coordinating to the oxygen lone pairs of the P-O moiety of the spiro ring.     

Side group functionalized liquid crystalline polymers and blends VIII. Nematic and SmAre phase formation in hydrogen-bonded blends of smectic side group LC polymers and a low molar mass dopant

Hydrogen-bonded blends based on smectic side group functionalized LC copolymers containing 4-alkyloxybenzoic acid fragments (proton donor) and a non-mesogenic low molecular mass dopant 4-cyanophenyl pyridine-4-carboxylate or 4-methoxyphenyl-d₄ pyridine-4-carboxylate (proton acceptor) were obtained. The blends containing 10-35 mol % of low molecular weight dopant form nematic (I-N-SmA) or re-entrant SmA phases (I-SmA-N-SmAre). The temperature dependence of the order parameter S, the birefringence Δn, and the splay K ₁ and bend K ₃ elastic constants of the nematic phase were studied by ²H NMR spectroscopy and the Fréedericksz method of threshold transitions in a magnetic field. A mechanism for the destruction of the SmA phase and the formation of the nematic phase in the hydrogen-bonded blends is suggested.     

Synthesis,spectroscopic characterization and density functional studies of a bis-benzimidazole derivative and of its complexes with palladium(II) halides

The 2,6-bis(benzimidazol-2′-ylthiomethyl)pyridine (L) ligand and its palladium(II) complexes [Pd(L)X]X (X = Cl, Br, and I) have been synthesized and characterized by spectroscopic data acquisition. The ligand (L) was prepared by conventional heating as well as by microwave irradiation. Microwave irradiation shows additional features, including an easy workup, a much faster reaction and higher yields. The molar conductivity data reveal that the complexes form a 1:1 electrolyte in DMSO. The geometries, ground-state energetics and vibrational spectra of (L) and of its complexes have been elucidated, in terms of quantum chemical calculations. In the mononuclear complexes, the palladium atom is coordinated to three nitrogen atoms and one terminal halogen atom in a slightly distorted square planar arrangement. The present elemental analyses, FT–IR (mid, far), ¹H and ¹³C NMR spectra are in good accordance with the square planar geometry around the Pd ion. The thermal behaviors of the complexes have been assessed by thermal gravimetric and differential thermal analyses.     

Carboxylic acid recognition of diamidine having a fluorescent 1,8-diphenylanthracene unit and its detection of amidinium-carboxylate and amidinium formation

A diphenylanthracene-based diamidine (1a) fluorescent probe for the detection of dicarboxylic acids has been designed and synthesized, which has an extended π-conjugation rather than a simple anthracene ring, in order to observe highly different fluorescence wavelengths after complex formation with dicarboxylic acids. The fluorescence spectra of the mixed solution of the diamidine 1a and carboxylic acids showed two different fluorescence bands, which corresponded to the complex formation (amidinium-carboxylate formation, λ_em?=?450?nm, light blue color) and dissociated amidinium formation (λ_em?=?510?nm as a broad band, green color). The complexed and dissociated states were confirmed by DOSY NMR and TD-DFT calculations. These different fluorescence wavelengths may come from the differences in the dihedral angles between the phenyl rings at the 1,8-position and anthracene ring (difference in π-conjugation) of 1a under complex formation and dissociated amidinium formation. The proposed mechanism for the observation of the different fluorescence wavelengths (complex formation and amidinium formation) was also confirmed by the fluorescence study of diamidine 1b which causes restricted rotation of the phenyl rings by substitution of the steric methyl groups, and observed the same fluorescence spectra for the complex formation and amidinium formation (400, 420, 450?nm as a vibrational structure of anthracene ring). These fluorescence characteristics of the diamidine 1a are also applicable for the detection of α,ω?dicarboxylic acids.     

Synthesis of optically active fluoroadamantane derivative having different substituents on its tert-carbons and its use as a non-racemizable source for new optically active adamantane derivatives

Enantiomerically pure methyl 3-fluoro-5-methyladamantane-1-carboxylate was obtained by the separation of its racemate, which was prepared from methyladamantane-1-carboxylate in three steps in 86% overall yield. From the resulting pure enantiomers, a new optically active adamantane compound was prepared by the substitution of a fluorine atom with a phenyl group. Both enantiomers of 3-amino-5-methyladamantane-1-carbooxylic acid were also prepared.     

N‐N migration of a carbamoyl group in a pyrazole derivative revealed by NMR

During a synthesis of 5‐amino‐4‐(6‐methoxy‐2‐methylpyridin‐3‐yl)‐3‐methyl‐1H‐pyrazole‐1‐carboxamide (see Scheme 1), a side‐reaction produced 3‐amino‐4‐(6‐methoxy‐2‐methylpyridin‐3‐yl)‐5‐methyl‐1H‐pyrazole‐1‐carboxamide as a by‐product that forms an equilibrium with the target‐compound. The structure of the by‐product was elucidated by the interpretation of 1D and 2D (HMQC, HMBC) NMR data where ¹H‐¹⁵ N HMBC correlations revealed the position of carbamoyl group attachment on the pyrazole. Comparison of structures of the target‐compound and the by‐product showed that the latter resulted from N‐N migration of the carbamoyl group in the target‐compound. Copyright © 2013 John Wiley & Sons, Ltd.     

一种黄酮衍生物的合成及其体外抗癌活性

以柚皮素为原料,通过对其结构进行修饰,合成了黄酮衍生物5-羟基-2-(4-羟基苯基)-7-(2-吗啉基乙氧基)-4H-苯骈吡喃-4-酮;利用核磁共振、元素分析及质谱确认了产物的结构,利用MTT法测定了其对人肝癌细胞(HepG2)、7721以及QSG7701正常肝细胞株的抑制率.结果表明,同槲皮素相对照,合成的黄酮衍生物对肝癌细胞具有良好的抑制活性.     

一种萘酰亚胺衍生物的合成及其体外抗癌活性测定

合成了萘酰亚胺衍生物2-[2-(二甲基氨基)乙基]-6-2-(2-羟乙胺基)乙胺基-1H-苯并异喹啉-1,3(2H)-二酮;利用元素分析、核磁共振谱及质谱分析了其组成和结构;利用MTT法测定了其对人肝癌细胞(HepG2)、人乳腺癌细胞(MDA-MB-231)及人结肠癌细胞(HCT-116)的体外活性.结果表明,标题化合物的体外抗肿瘤活性优于对照品氨萘非特.     

Modeling the time and temperature dependence of the oPs formation probability in polystyrene and its derivatives

Positron annihilation lifetime spectroscopy measurements of polystyrene and its derivatives have been performed in the temperature range 20–300 K. The ortho‐positronium lifetime calculated from the lifetime spectrum analysis is related to the mean free‐volume hole size. However, the ortho‐positronium yield in the medium is dependent on the polymer chemistry and also on the irradiation effect induced by the positron source. We proposed a model based on two simple processes that cause, respectively, enhancement and inhibition of positronium formation to fit the experimental data over a broad temperature range. Using this model, intrinsic parameters for the polymers under study, such as the shallowly trapped electron recombination energy and the free‐radical recombination energy, were calculated and discussed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2063–2073, 2009     

Micelle formation of a diblock copolymer having pyridine as pendant groups by carboxylic acids in nonselective solvents

The micelle formation of a poly(4-pyridinemethoxymethylstyrene)-block-polystyrene diblock copolymer (PPySt-b-PSt) was investigated in nonselective solvents using bifunctional and trifunctional carboxylic acids. The copolymer showed no self-assembly in 1,4-dioxane and tetrahydrofuran (THF) because the PPySt and PSt blocks were solvophilic to the solvents. Dynamic light scattering studies demonstrated that the copolymer formed micelles in the nonselective solvents in the presence of bifunctional carboxylic acids. Oxalic acid, maleic acid, citric acid, and phospholic acid promoted the micellization, while malonic acid, succinic acid, and glutalic acid had no effect on the micellization. The micellar size, aggregation number, and critical micelle concentration were dependent not only on the acid strength but also on the type of acid and the functionality. The micellization was also affected by the solvent quality. The micellization proceeded more effectively in 1,4-dioxane than in THF. It was found that the micellization occurred by hydrogen bonding between the pyridine moiety and the carboxylic acid and by the interaction among the carboxylic acids. This is because the copolymer needed over an equivalent of the acid to the PySt unit to complete the micellization. Furthermore, monofunctional carboxylic acid such as trichloroacetic acid and trifluoroacetic acid promoted the micellization, although dichloroacetic acid had no effect on the micellization.     

The use of the temperature signal and its derivative in a TG-DTA simultaneous unit

Simultaneous TG-DTA units have a work station which allows plots to be made of temperature against time, as well as the conventional TG and DTA plots. These time-temperature plots and their derivatives can be used to show details of both exothermic and endothermic events. The melting behavior of zinc is used as illustrative of endothermic phase changes. Solid-solid transitions are exemplified by noting the transitions in quartz. Examples of chemical reactions being treated to temperature-time plots are the decomposition's of zinc oxalate in nitrogen (an endothermic event) and the oxidation of carbon black in air (a sustained exothermic event). This wide selection of exothermic and endothermic events serves to illustrate the details which can be drawn from any thermogravimetric plot irrespective of the other associated equipment present, which serves to reinforce the data presented in the present study.     

Direct electrosynthesis and characterization of a new soluble polyfluorene derivative containing carboxyl group in boron trifluoride diethyl etherate

High-quality poly(fluorene-9-acetic acid) (PFAA), a new soluble polyfluorene derivative, was synthesized electrochemically by direct anodic oxidation of fluorene-9-acetic acid (FAA) in boron trifluoride diethyl etherate (BFEE) containing a certain amount of trifluoroacetic acid (TFA). This electrolyte enables facile anodic oxidation of FAA monomer at lower potential (1.05 V vs. SCE). PFAA films with conductivity of 0.53 S cm⁻¹ obtained from this medium showed better redox activity and thermal stability in relation to unsoluble poly(fluorene-9-carboxylic acid). Fluorescent spectral studies indicate that PFAA film with high fluorescence quantum yields and photochemical stability is a good blue-light emitter. The structure and morphology of the polymer were studied by UV–vis, FT-IR, ¹H NMR spectra and scanning electron microscopy, respectively.     

Synthesis and micropatterning properties of a novel base‐soluble,positive‐working,photosensitive polyimide having an o‐nitrobenzyl ether group

A novel positive‐working, photosensitive polyimide, poly[1,4‐phenyleneoxy‐1,4‐phenylene‐2,2′‐di(2‐nitrobenzyloxy)benzophenone‐3,3′,4,4′‐tetracarboxdiimide] (OPI‐Nb), developable with an aqueous base was prepared by the o‐nitrobenzylation of a polyimide, poly(1,4‐phenyleneoxy‐1,4‐phenylene‐2,2′‐dihydroxybenzophenone‐3,3′,4,4′‐tetracarboxdiimide) (OPI), derived from 2,2′‐dihydroxy‐3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (DHBA) and 4,4′‐oxydianiline, and it micropatterning properties were investigated. The o‐nitrobenzylation of OPI to OPI‐Nb was conducted with o‐nitrobenzyl bromide in N‐methyl‐2‐pyrrolidinone containing Et₃N. The DHBA monomer was synthesized by exhaustive KMnO₄ oxidation of bis(2‐dimethoxy‐3,4‐dimethylphenyl)methane obtained by etherification of bis(2‐hydroxy‐3,4‐dimethylphenyl)methane with iodomethane, followed by deprotection of the methoxy groups and cyclodehydration of the obtained 2,2′‐dihydroxy‐3,3′4,4′‐benzophenonetetracarboxylic acid. The intermediate bis(2‐hydroxy‐3,4‐dimethylphenyl)methane was prepared by the condensation of 2,3‐dimethylphenol with paraformaldehyde. The degree of o‐nitrobenzylation was determined to be over 94 mol % from ¹H NMR absorption of benzylic CH₂ protons. The aromatic OPI was perfectly soluble in a dilute aqueous NaOH solution and tetramethylammonium hydroxide (TMAH), whereas OPI‐Nb was not even swellable in them. In the micropatterning process, OPI‐Nb showed a line‐width resolution of 0.4‐μm and a sensitivity of 5.4 J/cm² when its thin films were irradiated with 365‐nm light and developed with a 2.38% aqueous TMAH solution at room temperature for 90 s. The thickness loss of OPI‐Nb films measured after postbaking at 350 °C was in the 8–9% range. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 776–788, 2007     

Assessment of the effect of N-oxide group in a new high-performance energetic tetrazine derivative on its physicochemical and thermodynamic properties,sensitivity, and combustion and detonation performance

Chemistry of Heterocyclic Compounds - This work uses density functional theory and suitable predictive methods to assess the effect of N-oxide group in 1,2-bis(6-nitro-1,2,4,5-tetrazin-3-yl)diazene...     

Control of the CT interaction between electron-donor and -acceptor moieties of a 1,4-dicyanonaphthalene-arene dyad for intermolecular exciplex or excimer formation in crystals

Colorless crystals of 1,4-dicyano-2-(4′-methoxybenzyloxy)methylnaphthalene (2), which is a 1,4-dicyano-2-methylnaphthalene (DCMN)-4-methylanisole (MA) dyad linked by an ether unit, selectively form a fluorescent intermolecular DCMN-MA exciplex (greenish blue, ). In contrast, 1,4-dicyano-2-(4′-methylbenzyloxy)methylnaphthalene (3), which is a DCMN-p-xylene dyad, forms a fluorescent intermolecular DCMN-DCMN excimer in the crystalline state (blue, ). These findings demonstrate that a moderate charge transfer interaction takes place between the DCMN moiety of 2 and MA moieties of the adjacent molecules of 2, which successfully facilitates the preparation of light-emissive organic crystals.     

Synthesis and characterization of a polymerizable benzophenone derivative and its application in styrenic polymers as UV-stabilizer

In this paper, a polymerizable UV-stabilizer 2-hydroxy-4-(3-methacryloxy-2-hydroxylpropoxy) benzophenone (BPMA) was synthesized by the reaction of 2,4-dihydroxybenzophenone (UV-0) and glycidyl methacrylate (GMA), and characterized by ultraviolet-visible absorption spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (¹H NMR). The results show that BPMA, with high UV-absorbing performance, has been synthesized successfully. Poly(St-co-BPMA) was prepared by emulsion copolymerization of styrene (St) and BPMA, and tested by ¹H NMR, UV-Vis, gel permeation chromatography (GPC) and differential scanning calorimeter (DSC). The results reveal that BPMA had been added to the polymer chain as copolymer and the UV-resistant performance of poly(St-co-BPMA) was enhanced significantly by the incorporation of BPMA onto the polymer chains. Poly(St-co-BPMA) was irradiated under UV light and insoluble substance, reduced viscosity, weight loss and UV-Vis absorption spectra were used to determine the degradation of poly(St-co-BPMA). The results show that BPMA is an effective UV-stabilizer in protecting poly(St-co-BPMA) from UV destroys. We also take water extraction test on poly(St-co-BPMA), PSt/UV-0 blends, and the results show that migration problem can be resolved by anchoring the UV-stabilizer onto the polymer chain.