摘要 :
Cyclization of 8-bromo-9-alkylaminoethyl-adenine quantitatively affords a substituted imidazo[1,2-e]purine. The corresponding heterodimer, imidazo[1,2-e]purine-acridine, was prepared and its interaction with abasic site containing...
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Cyclization of 8-bromo-9-alkylaminoethyl-adenine quantitatively affords a substituted imidazo[1,2-e]purine. The corresponding heterodimer, imidazo[1,2-e]purine-acridine, was prepared and its interaction with abasic site containing oligonucleotides was studied.
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A stable carbocation was prepared by reacting bis(2-chloro-2,2-difluoroethyl)difluoroformal with SbF_5.The carbocation's structure was confirmed by ~(19)F,~1H and ~(13)C NMR measurements.The carbocation is stable at room temperatu...
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A stable carbocation was prepared by reacting bis(2-chloro-2,2-difluoroethyl)difluoroformal with SbF_5.The carbocation's structure was confirmed by ~(19)F,~1H and ~(13)C NMR measurements.The carbocation is stable at room temperature for more than 2 weeks and was converted into the corresponding carbonate when reacted with water.
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<abstract_text><p>The key intermediates 3H-imidazo[4 ',5 ':3,4]benzo[c] isoxazoles were synthesized by the reaction of N-alkyl-5-nitrobenzimidazoles with aryl acetonitriles under basic conditions. These compounds were converted to...
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<abstract_text><p>The key intermediates 3H-imidazo[4 ',5 ':3,4]benzo[c] isoxazoles were synthesized by the reaction of N-alkyl-5-nitrobenzimidazoles with aryl acetonitriles under basic conditions. These compounds were converted to 3H-imidazo[4,5-a]acridin-11(6H)-ones by the Tanasescu reaction in excellent yields. The structures of all newly synthesized compounds were confirmed by IR, H-1 NMR, and mass spectroscopic data. The interactions of 3H-imidazo[4,5-a] acridin-11-ones with human serum albumin (HSA) have been studied by fluorescence spectroscopy. The binding of 3H-imidazo[4,5-a] acridin-11(6H)-ones quenches the HSA fluorescence, revealing a 1 : 1 interaction with a binding constant of about 4.50 x 10(4) - 1.25 x 10(5) M-1. A decrease in the fluorescence intensity at 339.41 nm, when excited at 280 nm, is attributed to changes in the environment of protein fluorophores caused by the presence of the ligands. Differences in the interactions of 3H-imidazo[4,5-a] acridin-11(6H)-one derivatives with HSA were observed using the spectrofluorimetry technique. Thermodynamic characteristics and the parameters of HSA binding with these compounds are in accordance with the antibacterial activity of various derivatives of 3H-imidazo[4,5-a] acridin-11(6H)-one.</p></abstract_text>
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The directed synthesis of a noval tetracyclic heteropolyphosphane skeleton from a tricyclophosphane has been achieved by condensation of Li3P7 . 3DME with Cl(Et2N)B-B(NEt2)Cl to the diboranonaphosphanide LiP7(BNEt2)(2) (1). When t...
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The directed synthesis of a noval tetracyclic heteropolyphosphane skeleton from a tricyclophosphane has been achieved by condensation of Li3P7 . 3DME with Cl(Et2N)B-B(NEt2)Cl to the diboranonaphosphanide LiP7(BNEt2)(2) (1). When the reaction proceeds the mixed-substituted diboranonaphosphane P-7(BNEt2)(4)Cl (2) is formed. According to their P-31 NMR spectra I and 2 possess a B2P7(3) skeleton analogous to that of the hydrocarbon deltacyclane. Additional weak signals in the P-31 NMR spectrum of 2 indicate that also small amounts of the symmetrically substituted diborane(4) P14B6(NEt2)(6) (3) are formed. [References: 17]
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The synthesis and structural assignments of 9-chloro-1,1-phenanthroline-2(1H)-thione and 1,10-dihy-dro-1,10-phenanthroline-2,9-dithione have been accomplished. The sulfur-bridged bis-1,10-phenanthro-line macrocycle was readily pre...
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The synthesis and structural assignments of 9-chloro-1,1-phenanthroline-2(1H)-thione and 1,10-dihy-dro-1,10-phenanthroline-2,9-dithione have been accomplished. The sulfur-bridged bis-1,10-phenanthro-line macrocycle was readily prepared by heating the thione or equimolar amounts of the dithione and 2,9-dichloro-1,10-phenanthroline in diphenyl ether. Displacements of 2-chloro-or 2,9-dichloro-1,10-phenanthroline with N,N-dimethylethylenediamine afforded the corresponding amine and diamino analogues. An amino-substituted-2,2'-bis-1,10-phenanthroline has been prepared.
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A facile ring closure reaction of mitoxantrone for the preparation of naphtho[2,3-f]quinoxaline-7,12-dione 3a was studied and optimized. This method allows the preparation of 3a in multigram quantities without the need for chromat...
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A facile ring closure reaction of mitoxantrone for the preparation of naphtho[2,3-f]quinoxaline-7,12-dione 3a was studied and optimized. This method allows the preparation of 3a in multigram quantities without the need for chromatography. [References: 25]
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Reaction of binucleophiles with 1,4- and 1,3-bis(2-chloro-2-cyanovinyl) benzenes, synthesized using a catalytic olefination of terephthalic and isophthalic aldehydes, gave high yields of aminopyrazoles, 3-amino-5- arylthiophene-2-...
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Reaction of binucleophiles with 1,4- and 1,3-bis(2-chloro-2-cyanovinyl) benzenes, synthesized using a catalytic olefination of terephthalic and isophthalic aldehydes, gave high yields of aminopyrazoles, 3-amino-5- arylthiophene-2-carboxylic acid esters, and 2,4-diamino-6-arylpyrimidines.
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OBJECTIVES: Physical disability in patients with rheumatoid arthritis (RA) is often assessed by questionnaires. We compared the Health Assessment Questionnaire (HAQ) with the modified HAQ (MHAQ) in a cohort of RA patients across v...
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OBJECTIVES: Physical disability in patients with rheumatoid arthritis (RA) is often assessed by questionnaires. We compared the Health Assessment Questionnaire (HAQ) with the modified HAQ (MHAQ) in a cohort of RA patients across various levels of disability, and examined correlations with other measures of physical function. METHODS: Patients with RA (n = 182) completed self-report questionnaires assessing functional capacity. Instruments included the MHAQ and HAQ completed separately, as well as SF-36 and the Arthritis Impact Measurement Scales (AIMS). Scores from unadjusted and adjusted HAQ were compared with MHAQ at various disability levels. RESULTS: A clear ceiling effect with aggregation of normal scores for physical function was observed for MHAQ (23%) and HAQ (12%), but not for SF-36 (4%) or AIMS (5%). The correlations between adjusted/unadjusted HAQ and MHAQ scores were 0.85/0.88. A discrepancy in HAQ and MHAQ scores was observed in patients with high levels of disability, especially when MHAQ was compared with the adjusted final HAQ score. Adjustment of HAQ by aids or help increased the final score by an average of 0.15, and both adjusted and unadjusted HAQ scores were numerically clearly higher (mean 0.45 and 0.30, respectively) than the MHAQ score. CONCLUSION: The present findings indicate that MHAQ and HAQ may be applicable as measures of physical capacity in RA patients, but clinicians and researchers should select the appropriate instrument for the setting, and be aware of differences in scores, especially at different disability levels.
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A novel fluorinated diamine monomer, 9,9-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]fluorene (II) was prepared via the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride with 9,9-bis(4-hydroxyphenyl)fluoren...
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A novel fluorinated diamine monomer, 9,9-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]fluorene (II) was prepared via the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride with 9,9-bis(4-hydroxyphenyl)fluorene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides V were synthesized from diamine II and various aromatic dianhydrides IIIa-f via thermal imidization. These polymers had inherent viscosities ranging from 0.84 to 1.03 dL/g and were soluble in a variety of organic solvents such as NMP, DMAc, DMF, and DMSO, and some could even be dissolved in less polar solvents such as m-cresol, pyridine, and dioxane. Polyimide films Va-f had tensile strengths of 85-105 MPa, elongations to break of 7-9%, and initial moduli of 2.13-2.42 GPa. The glass transition temperature of these polymers were in the range of 277-331degreesC, their 10% weight loss temperatures were in the range of 539-594degreesC in nitrogen and above 544degreesC in air, and their char yields at 800degreesC in nitrogen ranged between 55-65 wt%. Compared with nonfluorinated polyimides VI, V showed better solubility and lower color intensity. Low dielectric constants (2.68-2.85 at 1 MHz) and low moisture absorptions (0.12-0.24 wt%) were also observed. In particular, Vc-f afforded lightly-colored films, which had cutoff wavelengths lower than 385 nm and b* values ranging from 6 to 22.
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摘要 :
A novel emitting amorphous molecular material with a high glass-transition temperature of 158 deg C, 2,5-bis{4-(bis-(9,9-dimethyl-2-fluorenyl)amino)phenyl}thiophene (BFA-1T), has been developed. BFA-1T emits greenish blue light wi...
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A novel emitting amorphous molecular material with a high glass-transition temperature of 158 deg C, 2,5-bis{4-(bis-(9,9-dimethyl-2-fluorenyl)amino)phenyl}thiophene (BFA-1T), has been developed. BFA-1T emits greenish blue light with a relatively high fluorescence quantum yield of 0.48 in solution. A multilayer organic electroluminescent device using BFA-1T emitted greenish blue light with a maximum luminance of 12350 cd m~(-2) at 11 V with a luminous efficiency of 1.1 lm W~(-1) at a luminance of 300 cd m~(-2). The device worked even at 170 deg C.
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