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1.
Long-term exposure of nifedipine to daylight in ethanol gives 2,2"-bis[3,5-bis(methoxycarbonyl)-2,6-dimethylpyridin-4-yl]azoxybenzene and 6-hydroxy-1-methoxycarbonyl-2,4-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine as the major products. 相似文献
2.
《Analytical letters》2012,45(9):2075-2082
Abstract A spectrophotometric method for nickel has been developed based on the formation of a ternary complex in the system Ni(II)/3-(4′,5′-dimethyl-2′-thiazolylazo)-2,6-dihydroxybenzoic acid/cyanide at pH 9.2 (borate buffer), which allows the determination of 0.05–0.47ppm of nickel (ε = 3.53×104 1.mol?1. cm?1) at 538nm. Interferences have been studied and the method applied to the determination of nickel in low alloy steels. 相似文献
3.
L. G. Delyatitskaya M. V. Petrova S. Grinberga N. N. Tonkikh A. Ya. Strakov 《Chemistry of Heterocyclic Compounds》2000,36(6):728-732
Treatment of 3,6,6-trimethyl-4-oxo-1-(2-pyridyl)-4,5,6,7-tetrahydroindazole with sodium azide in acids gives 3,7,7-trimethyl-5-oxo-1-(2-pyridyl)-5,6,7,8-tetrahydro(4H)pyrazolo[4,3-b]azepine. Heating 1-(2-pyridyl)-3,6,6-trimethyl- and 1-phenyl-6,6-dimethyl-4-hydroxyimino-4,5,6,7-tetrahydroindazoles in polyphosphoric acid gives 1-phenyl-5,6-dimethyl- and 1-(2-pyridyl)-3,5,6-trimethyl-4-aminoindazole respectively: The reactions of the latter with 4-dimethylaminobenzaldehyde gave the 4-(4-dimethylaminobenzalamino) derivative and with 2-formyldimedone the 4-(4,4-dimethyl-2,6-dioxocyclohexylidenemethylamino) derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 830–834, June, 2000. 相似文献
4.
Simons electrochemical fluorination (ECF) of 1,4-dimethyl-1,4-homopiperazine, methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine was studied. For comparison, ECF of three piperazines with a N-(methoxycarbonylmethyl) group(s) was also studied. ECF of 1,4-dimethyl-1,4-homopiperazine gave a low yield of corresponding perfluoro(1,4-dimethyl-1,4-homopiperazine) together with perfluoro(2,6-diaza-2,6-dimethylheptane) as the major product. Corresponding perfluoro(homopiperazines) with mono- and/or di-(fluorocarbonyldifluoromethyl) groups [CF2C(O)F] at the 1- and/or 4-position were formed in low yields from methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine, respectively. These new seven-membered perfluoro(1,4-dialkyl-1,4-homopiperazines) were accompanied by the formation of mono- and/or di-basic linear perfluoroacid fluorides resulting from the CC bond scission at the 2- and 3-positions of the ring. From mono- and/or di-N-(methoxycarbonylmethyl)-substituted piperazines, corresponding perfluoropeperazines having the acid fluoride group(s) were formed in low yields. 相似文献
5.
G. D. Gamalevich A. L. Vlasyuk V. A. Voblikova E. P. Serebryakov 《Russian Chemical Bulletin》2000,49(7):1313-1315
The biologically inactive (+)-enantiomer of 4-(2,6-dimethylheptyl)benzoic acid was converted into the known (R)-3,7-dimethyloctanol withee≥96% by ozonolysis followed by a two-step reduction of the ozonide. This confirmed theR configuration of the starting acid, theS configuration of its biologically active levorotatory antipode, and the absolute configurations assigned to their synthetic
precursors.
Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1316–1318, July, 2000. 相似文献
6.
7.
L. Yu. Ukhin O. V. Shishkin V. N. Baumer O. Ya. Borbulevych 《Russian Chemical Bulletin》1999,48(3):561-566
Benzimidazole-2-carbaldehyde reacts with 1-morpholinocyclohexene, 1-morpholinocyclopentene, and aminocrotonic ester upon heating
to form 4a,11-dimorpholino-1,2,3,4,11,11a-hexahydro-4aH-indolo[1,2-a]benzimidazole, 2-(2-morpholino-4,5-dihydrofulvenyl)benzimidazole, and 4-(benzimidazol-2-yl)-3,5-diethoxycarbonyl-2,6-dimethyl-1,4-dihydropyridine,
respectively.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 566–571, March, 1999. 相似文献
8.
Rohde M Schenk JA Heymann S Behrsing O Scharte G Kempter G Woller J Höhne WE Warsinke A Micheel B 《Applied biochemistry and biotechnology》1998,75(1):129-137
A panel of monoclonal antibodies was generated against the ureabased haptenN-(2-N-chloroacetylaminobenzyl)-N′-4-chlorophenylurea as a tool for building up sensitive immune assays to detect urea derivatives
and to screen them for catalytic antibodies (Abs). Eleven hybridomas were obtained that produced Abs reactive to the hapten.
All Abs were of IgG class. Crossreactivities of the Abs to different haptens were examined, especially to a possible transition-state
analog. Only four of the hybridomas (R2-DA10/F7, R2-GE7/H2, R2-HC2/A5, R2-HD6/F7) produced Abs crossreactive with the transition-state
analog. From the 11 hybridomas, hybridoma B76-BF5 was chosen for further characterization. Compared to the other Abs, B76-BF5
showed the strongest binding and had a rather restricted specificity. These Abs could be used to build up a sensitive enzyme
immunoassay for the detection of the hapten. All Abs were screened for crossreactivity with the pesticides monuron and diuron.
No reactivity could be detected. In addition, the nucleotide sequences of the variable light and heavy chain genes of the
similarly reactive Abs B76-BF5, B76-BB3, R2-DA10/F7, and R2-GA6/G3 were determined to clarify whether structure and binding
specificity of these Abs showed any correlation. 相似文献
9.
Andreas J. Schuetz Michael Winklmair M. G. Weller Reinhard Niessner 《Fresenius' Journal of Analytical Chemistry》1999,363(7):625-631
A multianalyte immunosensor array can be implemented by immobilization of different haptens in distinct areas of a single
cavity or flow cell. In this case a mixture of different antibodies for different analytes is used in an indirect ELISA-format.
The selection of the right hapten structures is very important to build up an array successfully. A system of independent
hapten/antibody combinations is needed, with one immobilized hapten (coating antigen) reacting only with one antibody. If
more than one antibody binds to a coating antigen no ideal calibration curves are obtained. This phenomenon is known as shared-reactivity
and can lead to double-sigmoidal curves. To use monoclonal antibodies to 2,4,6-trinitrotoluene (TNT) and 2,4-dichlorophenoxyacetic
acid (2,4-D), two different haptens had to be found, one only reacting with the TNT-antibody, the other only binding to the
2,4-D-antibody. 2,4-Dichlorophenoxybutyric acid was used for the 2,4-D antibody and 2,4,6-trinitrophenyl-8-aminooctanoic acid
for the TNT antibody. Although 4-nitrotoluene, 2,4-dinitrotoluene and 4-amino-2,6-dinitrotoluene showed only very low cross-reactivities
to the 2,4-D antibody the corresponding haptens 4-nitrophenylacetic acid, 2,4-dinitrophenyl-6-aminohexanonic acid, and 4-amino-2,6-dinitrotoluyl-(N)-glutarate
are useful coating antigens for this antibody. The structure of the coating antigens had no significant influence on the midpoints
(IC50) of the test for 2,4-D and even haptens with very low cross-reactivities could be used. With all haptens a test midpoint
of about 0.2 μg/L for 2,4-D was achieved. For the direct assay format with immobilized antibodies the same test midpoint of
0.2 μg/L for 2,4-D was obtained. As a conclusion, the selectivity of a monoclonal antibody should not be influenced by the
used tracer or coating antigen as well. It could be shown that the affinity constants of an antibody to the analytes are the
main sensitivity and selectivity determining parameters for competitive immunoassays. A two-dimensional microtiter plate array
was used to determine the analytes 2,4-D and TNT in parallel with a mixture of antibodies.
Received: 29 July 1998 / Revised: 21 October 1998 / Accepted: 10 November 1998 相似文献
10.
E. Nemčeková A. Rybár G. Nosál'ová J. Alföldi 《Monatshefte für Chemie / Chemical Monthly》1995,126(6-7):799-804
Summary Alkylation of 8-vinyl-1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione (1) with alkyl halides inDMF in the presence of potassium carbonate, or alternatively, alkylation of its sodium salt (2) with alkyl iodide or hydroxyalkyl iodide afforded the 7-alkyl- or 7-(-hydroxyalkyl)-8-vinyl-1,3-dimethyl-3,7-dihydro-1H-purine-2,6-diones3. 2-Substituted oxiranes reacted with1 catalyzed by2 or Triton B to yield 7-(2-hydroxyalkyl)-8-vinyl-1,3-dimethyl-3,7-dihydro-1H-purine-2,6-diones4. Compounds3 and4 were tested for broncholytic activity. The most effective derivatives were3c and4b.
7-Substituierte 8-Vinyl-1,3-dimethyl-3,7-dihydro-1H-purin-2,6-dione und ihre broncholytische Wirkung
Zusammenfassung Alkylierung von 8-Vinyl-1,3-dimethyl-3,7-dihydro-1H-purin-2,6-dion (1) mit Halogenalkanen in Gegenwart von Kaliumkarbonat inDMF oder Alkylierung seines Natrium-Salzes (2) mit Iodalkanen beziehungsweise Iodalkanolen führte zu den 7-Alkyl- bzw. 7-(-Hydroxyalkyl)-8-vinyl-1,3-dimethyl-3,7-dihydro-1H-purin-2,6-dionen3. 2-Substituierte Oxirane reagierten mit Verbindung1 unter Katalyse durch2 oder Triton B zu den entsprechenden 7-(2-Hydroxyalkyl)-derivaten4. Die Substanzen3 und4 wurden auf ihre broncholytische Wirkung geprüft. Die höchste Aktivität wurde bei den Derivaten3c und4b festgestellt.相似文献
11.
以N-(2-异丙酸)-邻羟基苯甲酰腙(C10H10N2O4, H3L)、2,6-吡啶二甲酸(2,6-H2PDA)与RE(NO3)38226;nH2O (RE=Pr, Eu)在室温下反应, 合成了配合物1 [Pr2(H2L)2(HL)2(2,6-H2PDA)(H2O)2]8226;2H2O和配合物2 [Eu2(H2L)2(HL)2(2,6-H2PDA)- (H2O)2]8226;2H2O, 对其进行了元素分析、红外光谱、紫外光谱等表征, 测定了两种配合物的晶体结构. 通过紫外吸收光谱、荧光发射光谱和稳态荧光猝灭方法及其与溴化乙锭(EB)的竞争实验研究了两种配合物与小牛胸腺DNA的作用情况. 结果表明, 两种配合物与小牛胸腺DNA均是以插入方式结合的. 相似文献
12.
Chin-Ping Yang Sheng-Huei Hsiao Chun-Cheng Yang 《Journal of polymer science. Part A, Polymer chemistry》1997,35(11):2147-2156
2,6-Bis(4-aminophenoxy)naphthalene (2,6-BAPON) was synthesized in two steps from the condensation of 2,6-dihydroxynaphthalene with p-chloronitrobenzene in the presence of potassium carbonate, giving 2,6-bis(4-nitrophenoxy)naphthalene, followed by hydrazine hydrate/Pd—C reduction. A series of new polyamides were synthesized by the direct polycondensation of 2,6-BAPON with various aromatic dicarboxylic acids in the N-methyl-2-pyrrolidone (NMP) solution containing dissolved metal salts such as CaCl2 or LiCl using triphenyl phosphite and pyridine as condensing agents. The polymers were obtained in quantitative yields with inherent viscosities of 0.62–2.50 dL/g. Most of the polymers were soluble in aprotic dipolar solvents such as N,N-dimethylacetamide (DMAc) and NMP, and they could be solution cast into transparent, flexible, and tough films. The casting films had yield strengths of 84–105 MPa, tensile strengths of 68–95 MPa, elongations at break of 8–36%, and tensile moduli of 1.4–2.1 GPa. The glass transition temperatures of the polyamides were in the range 155–225°C, and their 10% weight loss temperatures were above 505°C in nitrogen and above 474°C in air. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2147–2156, 1997 相似文献
13.
O. V. Khilya T. A. Volovnenko A. V. Turov Yu. M. Volovenko 《Chemistry of Heterocyclic Compounds》2004,40(8):1063-1069
The interaction of 4-oxo-3,4-dihydroquinazolinyl- and benzimidazolylacetonitriles with 2,6-dihalobenzaldehydes leads to 3-(2,6-dihalophenyl)-2-(4-oxo-3,4-dihydro-2-quinazolinyl)acrylonitriles and 2-(1H-benzo[d]imidazol-2-yl)-3-(2,6-dihalophenyl)acrylonitriles respectively. As a result of intramolecular cyclization of these nitriles 4-halo-12-oxo-12H-quino[2,1-b]quinazoline-6-carbonitriles and 4-halobenzo[4,5]imidazo[1,2-a]quinoline-6-carbonitriles respectively are formed. 相似文献
14.
Determination of Dopamine Using 2-(4-Boronophenyl)quinoline-4-carboxylic Acids as Fluorescent Probes
The selective identification of dopamine is a significant issue because this compound is an important neurotransmitter closely related to Parkinson’s disease and other mental disorders. 2-(4-Boronophenyl)quinoline-4-carboxylic acid (PBAQA) has been previously reported as a water-soluble fluorescent probe for catechol. However, there are no significant differences in the binding constants between catechol and catecholamines, such as dopamine or levodopa. Here a series of bis-boronic acid compounds based on PBAQA were synthesized and the binding activities were characterized. As a representative compound, the binding constant of 4-(4-((3-(3-borono-4-chlorobenzamido)propyl)carbamoyl)quinolin-2-yl)boronic acid to dopamine is up to 104?L?mol?1 and much higher than previously reported boronic acid probes. Dopamine selectivity may be achieved by the variation of the substituents in the probe molecules. 4-(4-((3-(3-Borono-4-methoxybenzamido)propyl)carbamoyl)quinolin-2-yl)boronic acid has a stronger binding affinity to dopamine (Ka=5204?±?106?L?mol?1) than catechol (Ka=2588?±?273?L?mol?1) or levodopa (Ka=2383?±?273?L?mol?1). This fluorescence response was used for determining dopamine in a range from 5?×?10?5?mol?L?1 to 5?×?10?4?mol?L?1 with a detection limit of 7.7?×?10?6?mol?L?1. This compound has been successfully used for the assay of dopamine in rabbit plasma, exhibiting excellent specificity. It is believed that synthesized compounds hold great promise as practical platforms to monitor dopamine levels. 相似文献
15.
Gerhard Buchbauer Gabriele Püspök Adelheid Angermayer Elisabeth Silbernagel Marisa Manz 《Monatshefte für Chemie / Chemical Monthly》1987,118(3):387-398
The synthesis of 4-(3,3-dimethyl-2-exo-norbornyl)-2-methyl-2-buten-1-ol (5), an analogue of -santalol (1) has been described. One route to5 starts with isocamphenilanyl propionic acid (8) which can be prepared in 4 steps from isocamphenilanic acid (9). Also 4 steps lead from8 to the target molecule5 with an overall yield of 24%. By a second and more convergent route, starting from the very easily obtainable bicyclic ketone19, the allylic alcohol5 could be obtained again in 4 steps, but this time with an overall yield of 1.3%. A new and easy synthesis of isocamphenilanyl acetic acid (15), a potential starting material to5, has been described, also the preparation of some new isocamphane derivatives.
26. Mitt:Buchbauer G,Pernold W,Ittner M,Ahmadi MF,Dobner R,Reidinger R (1985) Monatsh Chem 116: 1209 相似文献
16.
17.
Chin-Ping Yang Sheng-Huei Hsiao Chun-Cheng Yang 《Journal of polymer science. Part A, Polymer chemistry》1998,36(6):919-927
A novel polymer-forming diimide–diacid, 2,6-bis(4-trimellitimidophenoxy)naphthalene, was prepared by the condensation reaction of 2,6-bis(4-aminophenoxy)naphthalene with trimellitic anhydride (TMA). A series of novel aromatic poly(amide–imide)s containing 2,6-bis(phenoxy)naphthalene units were prepared by the direct polycondensation of the diimide–diacid with various aromatic diamines using triphenyl phosphite (TPP) in N-methyl-2-pyrrolidone (NMP)/pyridine solution containing dissolved calcium chloride. Thirteen of the obtained polymers had inherent viscosities above 1.01 dL/g and up to 2.30 dL/g. Most of polymers were soluble in polar solvents such as DMAc and could be cast from their DMAc solutions into transparent, flexible, and tough films. These films had tensile strengths of 79–117 MPa, elongation-at-break of 7–61%, and initial moduli of 2.2–3.0 GPa. The wide-angle X-ray diffraction revealed that some polymers are partially crystalline. The glass transition temperatures of some polymers could be determined with the help of differential scanning calorimetry (DSC) traces, which were recorded in the range 232–300°C. All the poly(amide–imide)s exhibited no appreciable decomposition below 450°C, and their 10% weight loss temperatures were recorded in the range 511–577°C in nitrogen and 497–601°C in air. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 919–927, 1998 相似文献
18.
A new aromatic diamine, 4-(4-trifluoromethyl)phenyl-2,6-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]pyridine, was synthesized by a modified Chichibabin reaction of 4-(4-nitro-2-trifluoromethylphenoxy)acetophenone with 4-triflouromethylbenzaldehyde, followed by catalytic reduction. A series of fluorinated pyridine-containing aromatic poly(ether imide)s (PEIs) were prepared from the diamine monomer with various aromatic dianhydrides via conventional two-step thermal imidization method. The resulting PEIs had inherent viscosities values of 0.68–0.90 dL/g, and could be cast and thermally converted into transparent, flexible, and tough polymer films. These PEIs were predominantly amorphous, had good solubility in common solvents such as NMP, DMAc and m-cresol at room temperature, and displayed excellent thermal stability with the glass transition temperatures of 258–315?°C, the temperatures at 5% weight loss of 550–585?°C, and the residue of higher than 55% at 750?°C in nitrogen. Moreover, the PEIs films showed outstanding mechanical properties with tensile strengths of 74.8–103.5?MPa, tensile moduli of 1.08–1.45?GPa, and elongations at break of 10.6–24.4%. These PEIs also exhibited low dielectric constants of 2.81–2.98 (1?MHz) and water uptake 0.39–0.68%, as well as high optical transparency with the UV cutoff wavelength in the 350–378?nm range and the wavelength of 80% transparency in the range of 412–510?nm. 相似文献
19.
The aim of this work is to investigate the three-component reaction of 6-aminopenicillinic acid, aldehydes and ammonium acetate. The work was used SiO2-H2SO4 as a catalyst to promote the reaction under solvent-free conditions. A series of 5,5-dimethyl-2-(2-aryl-1H-imidazol-5-yl)-2,5-dihydrothiazole derivatives were obtained as the main product by this method. 相似文献
20.
T. V. Rybalova V. F. Sedova Yu. V. Gatilov O. P. Shkurko 《Journal of Structural Chemistry》2003,44(5):870-873
The crystal structure of 2,2'-bis[2,6-dimethyl-3,5-di(methoxycarbonyl)pyridinyl-4]azoxybenzene has been determined; the compound is formed as the major product of photodegradation of niphedipine subjected to prolonged exposure of its ethanolic solution to daylight and artificial illumination. It is established that in crystal, the above azoxy derivative has a trans configuration. 相似文献