7-硝基-8-羟基喹啉的合成

以8-羟基喹啉为原料,经硝化和脱磺酸基保护两步反应合成了7-硝基-8-羟基喹啉,总收率69％,纯度高于99％.其结构经1H NMR,13C NMR和HR-MS确证.     

锆-氟-7-碘-8-羟基喹啉-5-磺酸-EDTA-表面活性剂体系的荧光光度研究

在pH5.5～7.0的HAc-NaAc缓冲溶液中,锆与氟、7-碘-8-羟基喹啉-5-磺酸(H_2QSI)、EDTA及十六烷基三甲基溴化铵(CTMAB)形成五元荧光络合物,其组成为Zr(Ⅳ):F:H_2QSI:EDTA:CTMAB=1:2:1:1:4.络合物的最大激发波长(λ_(ex))为365nm,最大发射波长(λ_(em))为 500 nm.由此建立了锆的选择性好、灵敏度高的荧光测定新方法.方法的检测限为 0.8μg/L.测锆的线性范围为 0.0016～1.04 mg/L.应用于合金中锆的测定,结果满意.     

Spectrophotometry Studies of Uranyl Chelate of 7-Iodo-8-Hydroxyquinoline-5-Sulphonic Acid

Uranyl chelate of 7-iodo-8-hydroxyquinoline-5-sulphonic acid (ferron) has been studied spectrophotometrically in aqueous solution at 25° and at an ionic strength of 0.1 M. The formation of this chelate was pH dependent, and the optimum pH range was between 5.4 to 5.9, Its mole ratio of ligand to uranyl ion was found to be 2 to 1 stoichiometry and the stability constant, log K, was determined as 13.32±0.08. By using the wave-length of 365 mu, determination of trace amount of uranyl ion with the sensitivity of 0.54 γ/cm² was possible.     

The 7-Iodo-8-Quinolinol-5-Sulfonic Acid Chelates of Some Rare Earth Metal Ions

The dissociation constants of 7-iodo-8-quinolinol-5-sulfonic acid and the formation constants of it's chelates with La(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III) and Lu(III) have been determined potentiometrically in 1:1 v/v dioxane-water medium at 25±0.1°C and at an ionic strength of 1 with respect to sodium chloride.     

Rare earth chelates derived from 8-quinolinol

The composition and heat stabilities of trivalent lanthanide oxinates prepared by homogeneous precipitation (urea hydrolysis in the presence of acetic acid) have been studied. The products contain acetate ion; and the molar ratio oxinate/metal is less than three. Polymeric structures are proposed for these materials, Heat stability in an inert atmosphere, as determined by thermogravimetric, thermomanometric and differential thermal analyses, decreases with increasing atomic weight of the metal.     

7—碘—8—羟基喹啉—5—磺酸—溴化十六烷基三甲铵荧光光度法测定痕量镥

本文研究了镥－Ｆｅｒｒｏｎ－表面活性剂三元荧光体系的荧光特性，各种表面活性剂中以溴化十六烷基三甲铵的增敏效果最佳，与相应的二元体系相比较，灵敏度提高近１０倍。镥的测定下限可达８．８ｎｇ／ｍｌ。本法与Ｐ５０７萃取色谱分离法相结合可用于天然混合稀土氧化物中痕量镥的测定，结果较满意。     

Spectrophotometric Studies of Cerium(III) Chelate of 7-Iodo-8-Hydroxyquinoline-5-Sulphonic Acid

Cerium(III) chelate of 7-iodo-8-hydroxyquinoline-5-sulphonic acid(ferron) has been studied spectrophotometrically in aqueous solution at 25°C and at an ionic strength of 0.1M. The formation of this chelate was pH dependent, and the optimum pH range was between 5.5 to 6.0. Its mole ratio of ligand to cerium(III) ion was found to be 2 to 1 stoichiometry and the formation constant, logK, was determined as 10.15. Enthalpy and entropy changes characterizing the formation of the chelate have been calculated as follows: ΔG° =-13.85kcal mole^-1, ΔH°= ?5.03 kcal mole^-1, ΔS°=29.56 eu mole^-1. By using the wavelength of 370 nm, determination of trace amount of cerium(III) ion with the sensitivity of 0.056 was possible.     

Gallium(III) Extraction from Alkaline Solutions with 5-Amylthio-8-quinolinol

Equilibrium extraction of gallium(III) from alkaline solutions with 5-amylthio-8-quinolinol was studied.     

One-pot synthesis of 2-alkyl-7-amino-5-aryl-pyrazolo[1,5-a]pyrimidine-6-carbonitriles via a domino three-component condensation-oxidation reaction

A one-pot, domino three-component condensation reaction of an aldehyde, 3(5)-amino-5(3)-methylpyrazole and malononitrile in ethanol to give 2-alkyl-7-amino-5-aryl-pyrazolo[1,5-a]pyrimidine-6-carbonitrile in high yields at reflux condition without using any catalyst, is described.     

Supercritical carbon dioxide extraction equilibrium of gallium(III) with 2-methyl-8-quinolinol and 2-methyl-5-butyloxymethyl-8-quinolinol

This work performed fundamental studies for the extraction of gallium(III) with 2-methyl-8-quinolinol (HMQ) and 2-methyl-5-butyloxymethyl-8-quinolinol (HMO(4)Q) into supercritical carbon dioxide (SF-CO(2)) from a weakly acidic solution. The distribution constants of HMO(4)Q between aqueous and SF-CO(2) phases were determined at 45 degrees C, 8.6-20.4 MPa and I=0.1 M (H, Na)NO(3) (M=mol dm(-3)). At 45 degrees C and 15.7 MPa, gallium(III) was hardly extracted with HMQ into SF-CO(2), but was quantitatively extracted with HMO(4)Q in the pH range of 2.20-2.84. The extraction constant, K(ex, SF-CO(2)) (=[Ga(OH)(MO(4)Q)(2)](SF-CO(2))[H(+)](3)[Ga(3+)](-1)[HMO(4)Q](SF-CO(2))(-2)), of gallium(III) with HMO(4)Q was determined to be 10(-2.6+/-0.1) at 45 degrees C, 15.7 MPa and I=0.1 M (H, Na)NO(3), which was 63 times larger than that in heptane at 45 degrees C and 0.10 MPa. It was also found that the addition of 3,5-dichlorophenol as a synergist enhanced the extractability of gallium(III) with HMO(4)Q into SF-CO(2).     

Extraction of lanthanides with 8-quinolinol in the presence of 6-amino-4,4′-(5-nonyl)-2,2′-bipyridine

6-Amino-4,4′-(5-nonyl)-2,2′-bipyridine (ADNBP) is studied for adduct formation in combination with 8-quinolinol (HQ) for lanthanide extractions. Ytterbium, praseodymium and lanthanum are extracted as mixed complexes, LnQ₃ · ADNBP. 8-Quinolinol did not form self-adducts in these systems under the given conditions. Extractabilities are enhanced dramatically by ADNBP.     

Facile synthesis of 5-amino- and 7-amino-6-azaoxindole derivatives

An efficient approach for the formation of 5-amino- and 7-amino-6-azaoxindole derivatives was developed. 2-Amino-4-chloro-3-nitropyridine (8), and its 5-nitro-substituted regioisomer (9), respectively, were obtained by reaction with ethyl malonate. The resulting 2-amino-3/5-nitropyridine derivatives substituted in the 4-position with malonic acid diethyl ester (10, 11) were subjected to reductive cyclization yielding 3-ethoxycarbonyl-6-azaoxindole derivatives 4a and 5a. Protection of the amino function was not required. Intermediates 10 and 11 could also be converted to the corresponding 4-acetic acid ethyl esters 12 and 13 by dealkoxycarbonylation with LiCl, and subsequently cyclized under reductive conditions yielding 3-unsubstituted 5-/7-aminooxazindoles.     

Chemoselective synthesis of 5-amino-7-bromoquinolin-8-yl sulfonate derivatives and their antimicrobial evaluation

Abstract

A series of new 5-amino-7-bromoquinolin-8-ol sulfonate derivatives 5(a–j) were synthesized from 8-hydroxyquinoline through multi-step process with high yields using mild, efficient and conventional methods. Chemoselectivity was observed during the transformation of 5-amino-7-bromoquinolin-8-ol to 5-amino-7-bromoquinolin-8-ol sulfonate with various sulfonylchlorides exclusively to afford sulfonate derivatives. Also, the products were investigated for their in vitro antimicrobial activities and compared with the standard drugs. Among all the synthesized compounds 5-amino-7-bromoquinolin-8-yl biphenyl-4-sulfonate (5b) and 5-amino-7-bromoquinolin-8-yl 2-hydroxy-5-nitrobenzenesulfonate (5g) have showed potent antibacterial activity, whereas 5-amino-7-bromoquinolin-8-yl biphenyl-4-sulfonate (5b) and 5-amino-7-bromoquinolin-8-yl 2-hydroxy-5-nitrobenzenesulfonate (5g) possessed potent antifungal activities among all the tested pathogens.     

Complete facial selectivity in the Diels-Alder reaction of a 5-amino-5-carboxycyclopentadiene derivative

5-tert-Butoxycarbonylamino-5-carbethoxy-2-tert-butyldimethylsilyloxy-cyclopentadiene undergoes a Diels-Alder reaction exclusively from the face syn to the nitrogen functionality. Complete reversal of facial bias may be achieved, but at the cost of diminished reactivity, through steric shielding of the N-syn face.     

N8-芳基取代4-氨基-6-氯-7(8H)-蝶啶酮的合成

通过N4-芳基取代4,5,6-三氨基嘧啶与草酸二水合物环合, 得到N8-芳基取代4-氨基-5,8二氢-6,7-蝶啶二酮, 再经氯代, 得到新型N8-芳基取代4-氨基-6-氯-7(8H)-蝶啶酮, 用红外光谱、核磁共振氢谱、核磁共振碳谱、质谱和元素分析确证了其结构. 用X-ray单晶衍射测定了4-氨基-6-氯-8-对甲苯基-7(8H)-蝶啶酮(3a)的晶体结构, 证明了环合反应的区域选择性.