Reaction of 2-(2-oxoethylidene)furan-3(2H)-ones with isopropylidenehydrazides of aromatic carboxylic acids: Synthesis of 3-hydroxy-3-(2-oxoethyl)-2,3-dihydropyridazin-4(1H)-ones

3-Hydroxy-3-(2-oxoethyl)-6-phenyl-2,3-dihydropyridazin-4(1H)-ones were obtained by the reaction of methyl 3-oxo-5-phenylfuran-2(3H)-ylideneacetate or 2-[2-(4-chlorophenyl)-2-oxoethylidene]-5-phenylfuran-3(2H)-one with benzoic or p-nitrobenzoic isopropylidenehydrazides. Equilibrium C₍₅₎H and C₍₅₎H₂ tautomeric forms were detected in solutions of the 4-chlorophenyl derivatives in DMSO-d₆. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1156–1158, August, 2007.     

Novel (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles from (E)- and (Z)-3-styrylchromones: the unexpected case of (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles

An efficient synthetic method for the preparation of (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles has been developed. The reaction of (E)- and (Z)-3-styrylchromones with hydrazine hydrate afforded the corresponding (E)- and (Z)-4-styrylpyrazoles, respectively, saved 4′-nitro-derivatives where both (E)- and (Z)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations was discussed and the stereochemistry of all products was assigned by NMR experiments.     

Studies of intramolecular hydrogen bonds (IMHB): crystal and molecular structure of 2-(2′-hydroxy-phenyl)imidazoles

The molecular and crystal structure of 2-(2′-hydroxyphenyl)imidazole (2) and 1-methyl-2-(2′-hydroxyphenyl)imidazole (5) have been determined by X-ray analysis. Compound (2) presents a strong intramolecular hydrogen bond (IMHB) responsible for the planarity of the molecule. In both compounds the molecules form chains through N---H…O (compound 2) and O---H…N hydrogen bonds (compound 5) but giving rise to the same packing mode. Ab initio calculations (6–31G**) have been carried out on both compounds in order to study the effect of the IMHB on the structure.     

邻羟基α-叠氮苯乙酮衍生物的合成

以邻羟基苯乙酮衍生物为原料,经溴化反应和叠氮化反应合成了一系列邻羟基α-叠氮苯乙酮衍生物,其结构经1H NMR,13C NMR,IR及HR-MS表征.     

Synthesis and Crystal Structure Analysis of 2-（3,5-Di-tert-butyl-2-hydroxyphenyl）-2-（3,4- dimethylphenyl） Acetic Acid Dimethylamine Salt

A new compound 2-（3,5-di-tert-butyl-2-hydroxyphenyl）-2-（3,4-dimethylphenyl） acetic acid dimethylamine salt （[NH2（CH3）2][C24H31O3]） was synthesized and structurally determined. It is of monoclinic system, space group P21/c with a = 14.731（2）, b = 10.1185（10）, c = 17.065（2） A^°, β = 98.293（10）° ,Z = 4, V = 2517.0（6）A^°^3, Dc = 1.091 g/cm^3, F（000） = 904 and Mr= 413.58. The dihedral angle defined by two benzene rings is 98.23°.     

Extraction-spectrophotometric determination of trace iron (II) in sea water with 2-[2-(3,5-dibromopyridyl)azo]-5-diethylaminobenzoic acid

An extraction-spectrophotometric method is described for the determination of traces of iron(II) with 2-[2-(3,5-dibromopyridyl)azo]-5-diethyl-aminobenzoic acid. The reagent forms a stable and blue 12 iron/reagent complex that can be extracted into chloroform. The apparent molar absorptivity of the iron(II) complex is 1.09 × 10⁵ 1 mol^–1 cm^–1 at 624 nm in chloroform. The reagent is relatively selective; interferences from cobalt, copper, nickel and vanadium can be removed by using dimethylglyoxime and EDTA. The method is applied to the determination of iron (II) in sea water and aluminium alloys with good precision and accuracy.     

2-(4-羟基苯基)-3,3,3-三氟丙酸乙酯的合成研究

报道了以苯酚和三氟丙酮酸乙酯为起始原料,在温和条件下合成高产率的2-(4-羟基苯基)-3,3,3-三氟丙酸乙酯的一条新途径.该途径包括无水碳酸钾催化的苯酚与三氟丙酮酸乙酯间的亲电取代反应、由此形成的产物的选择性侧连羟基的氯代反应和随后的硼氢化钠还原反应.     

Synthesis, X-ray structure and properties of a new nitrite-bound copper(II) complex with 2-(3,5- dimethylpyrazol-1-ylmethyl)pyridine in a CuN4(O) coordination

Synthesis and characterization of a nitrite-bound copper(II) compound [CuL⁴)₂(ONO)]ClO₄ have been achieved (L⁴ = 2-(3,5-dimethylpyrazol-1-ylmethyl)pyridine]. The bidentate ligand L⁴ provides a pyridine and a pyrazole donor site; however, they are separated by a methylene spacer. The complex has been structurally characterized and it belongs to only a handful of complexes having nitrito-bound mononuclear copper(II) centre. The metal atom has a distorted square pyramidal geometry with the copper atom displaced from the equatorial plane by 0.25 Å. In MeCN solution the green complex exhibits a broad ligand-field transition at 655 nm with a shoulder at 675 nm and in dichloromethane-toluene glass (80 K) it exhibits an EPR spectral feature characteristic of the unpaired electron in the d_x²−y² orbital. Variable-temperature (80–300 K) magnetic susceptibility measurements in the solid state as well as room temperature measurement in MeCN solution reveal mononuclear magnetically dilute copper(II) centre. When examined by cyclic voltammetry (MeCN solution) it displays electrochemically irreversible Cu^II---Cu^I response [cathodic peak potential, E_pc (V vs saturated calomel electrode (SCE)): −0.32]. An oxidative response is observed at 1.14 V, probably due to bound-nitrite oxidation and is partially removed to generate a solvated complex at the electrode surface. The latter species gives rise to reversible Cu^II---Cu^I redox response [ ].     

Synthesis of (<Emphasis Type="Italic">E</Emphasis>)- and (<Emphasis Type="Italic">Z</Emphasis>)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles

Abstract  An efficient synthesis method for the preparation of a series of new (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles was developed. The reaction of (Z)- and (E)-3-styrylchromones with hydrazine hydrate afforded the corresponding (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles, except for nitro derivatives, where both (Z)- and (E)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations is discussed and the stereochemistries of all products were established by NMR experiments. Graphical abstract        

Selective Spectrophotometric Determination of Palladium (II) With 2-(5-Bromo-2-Pyridylazo)-5-(Diethylamino)-Phenol

Abstract

A spectrophotometric study of the Pd(II) complex of a reagent 2-(5-Bromo-2-Pyridylazo)-5-(diethylamino)-Phenol (5-Br-PADAP) is presented. A violet complex is formed at pH 3.53, and shows maximal absorbance at 585 nm with molar absorptivity of 3.86 × 10⁴ 1. mol^?1 cm^?1. Beer's law is obeyed up to 50 μ of Pd(II). The method offers the advantages of simplicity, high precision, requires no extraction and is very selective, where 5.0 mg Pt(VI) and 0.3 mg Au(III) ions do not interfere.     

Synthesis,characterization, NLO study,and antimicrobial activities of metal complexes derived from 3-(3-(2-hydroxyphenyl)-3-oxoprop-1-enyl)-4H-chromen-4-one and sulfanilamide

A series of metal(II) complexes ML (where M?=?Cu(II), Co(II), Ni(II), Zn(II), Mn(II), Cd(II), and VO(II)) have been prepared from 3-(3-(2-hydroxyphenyl)-3-oxoprop-1-enyl)-4H-chromen-4-one and sulfanilamide. The structures of the complexes have been investigated by elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, NMR, mass, and ESR spectral studies. Conductivity measurements reveal that the complexes are non-electrolytes, except the oxovanadium complex. Spectral and other data show square pyramidal geometry for oxovanadium and octahedral for the other complexes. The redox behaviors of the copper and vanadyl complexes have been studied through cyclic voltammetry. Antimicrobial activities of the compounds against several microorganisms indicate that some complexes have higher activity than free ligand. The compounds may serve as photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation efficiency of the ligand was found to be higher than that of urea and KDP.     

Synthesis and Crystal Structure of a New Quinazolinone Compound 2,3-Dihydro-2-（2-hydroxyphenyl）-3-phenyl-quinazolin-4（1H）-one

A new quinazolinone compound 2,3-dihydro-2-(2-hydroxyphenyl)-3-phenylquinazolin-4(IH)-one 3 ([C2oH16O2N2]-C2H5OH, Mr = 362.42) and compound 2-(2-hydroxybenzylidene-amino)-N-phenyl-benzamide 2 (C2oH16O2N2, Mr = 316.34) were prepared from a precursor of 2-amino-N-phenyl-benzamide 1 (C13H12ON2, Mr = 212.25). Compound 3 was characterized by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic,space group Pbca with a = 1.2889(11), b = 1.6170(14), c = 1.7729(15) nm, V= 3.695(6) nm^3, Z= 8, F(000) = 1536, Mr = 362.42, Dc = 1.303 g/cm^3, μ(MoKa) = 0.087 mm^-1, R = 0.0447 and wR= 0.0879. The crystal structure analysis indicates that the title compound has a two-dimensional network structure formed by hydrogen bonds and electrostatic interactions.     

Synthesis and characterization of binuclear manganese(IV,IV) and mononuclear cobalt(II) complexes based on 2-(2-hydroxyphenyl)-1H-benzimidazole

The bidentate benzimidazolic hpbm (1), [2-(2-hydroxyphenyl)-1H-benzimidazole], was obtained under mild conditions, and its corresponding metal complexes, di-µ-oxo dimanganese(IV,IV) [Mn₂O₂(hpbm)₄ · 2Py · 5H₂O] (2), and mononuclear complex [Co(hpbm)₂] (3), were prepared and characterized. The crystal structures of 2 and 3 have been established by X-ray diffraction. Complex 2 consists of two six-coordinate manganese(IV) coordinated to two hpbm ligands and bridged by two O^2? with a Mn–Mn distance of 2.777 Å. For 3, a Co(II) is coordinated to two deprotonated hpbm in a nearly tetrahedral environment. Hydrogen bonds play pivotal roles in constructing the dimensional structures of both the compounds.     

Liquid crystalline polyethers based on conformational isomerism. XIX. Synthesis and characterization of flexible polyethers based on 1-(4-hydroxyphenyl)-2-(2-r-4-hydroxyphenyl) ethane with H,F, CH3, Br,Cl, and CF3 as R groups

The synthesis of 1-(4-hydroxyphenyl)-2-(2-fluoro-4-hydroxyphenyl)ethane ( FBPE ), 1-(4-hydroxyphenyl)-2-(2-chloro-4-hydroxyphenyl)ethane ( CIBPE ), 1-(4-hydroxyphenyl)-2-(2-bromo-4-hydroxyphenyl)ethane ( BrBPE ), and 1-(4-hydroxyphenyl)-2-(2-trifluoromethyl-4-hydroxyphenyl)ethane ( CF₃BPE ), of the corresponding polymers based on 1,5-dibromopentane ( RBPE-5) , 1,8-dibromooctane ( RBPE-8 ), and of the copolymers based on various ratios of 1,5-dibromopentane and 1,8-dibromooctane [ RBPE-5/8(A/B )] is described. The phase transition temperatures and thermodynamic parameters of RBPE-5 and RBPE-8 polymers were compared to those of the corresponding polyethers based on 1,2-bis(4-hydroxyphenyl)ethane ( BPE ) and 1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane ( MBPE ) which were reported previously. Both isotropic-nematic transition temperatures and corresponding thermodynamic parameters (i.e., enthalpy and entropy changes) decrease in the following order of the substituent R: H > F > CH₃ > Cl > Br > CF₃. This order corresponds to the increase of the breadth of the RBPE molecules, and agrees with the similar trends observed in low molar mass liquid crystals.     

Synthesis and Characterization of 2,5-Bis(2-pyridyl)thiophene

2-[2-(Trimethylsilyl)ethynyl] pyridine ( 6 ) was prepared in 95% yield by reaction of 2-bromopyridine with trimethylsilylacetylene in triethylamine in the presence of bis(triphenylphosphine)Palladium(II) chloride and Copper(I) iodide. Desilylation of ( 6 ) by refluxing with sodium hydroxide in methanol (yield 95%) of 2-ethynylpyridine ( 5 ). Oxidative coupling of ( 5 ) in pyridine by oxygen in the presence of Copper(I) chloride gives 70% yield of 1,4-bis(2-pyridyl)1,3-butadiyne ( 4 ). Reaction of 4 with sodium sulfide affords 100% of 2,5-bis(2-pyridyl) thiophene ( 1 ).     

超声技术合成1,5-二-(4-羟基苯基)-1,4-戊二烯-3-酮

利用对羟基苯甲醛和丙酮为原料,以氯化氢气体为催化剂,超声波辐射下成功合成了1,5-二-(4-羟基苯基)-1,4-戊二烯3-酮(HPD).与传统方法相比,该方法具有反应时间短,操作简便及产率高等优点,并讨论了影响产率的因素.     

Synthesis and Structure of [Cu2（μ—NO2）（aepy）4]（ClO4）3 （aepy=2—（2—Aminoethyl）pyridine）

1 INTRODUCTION There has been great and considerable interest in the study of copper nitrite complexes because they are relevant to the study of copper-containing enzymes involved in the denitrification process[1]; in particular, copper-nitrite complexes are potentially relevant to the nitrite reductases[2] (the enzyme from Achromobacter Cycloclastes) which convert NO2－ to NO and/or N2O. Many attempts have been made to synthesize a variety of copper-nitrite complexes, in which the n…     

3-(N-取代苯基-2-乙酰胺基)硫基-4-N-取代邻羟苯基亚胺基-5-甲基-1,2,4-三唑类化合物的合成及生物活性研究

以对称二氨基硫脲为原料,与冰醋酸反应生成5-甲基-4-氨基-1,2,4-三唑-3-硫酮(1);在弱酸性条件下,1与取代水杨醛反应生成席夫碱中间体5-甲基-4-(N-取代邻羟苯基)亚胺基-1,2,4-三唑-3-硫酮(2a～2c);最后在碱性条件下分别与N-取代苯基-2-氯乙酰胺发生烷基化反应生成15种未见报道的目标化合物3-(N-取代苯基-2-乙酰胺基)硫基-4-(N-取代邻羟苯基)亚胺基-5-甲基-1,2,4-三唑(3a～3o),其结构经IR,1H NMR,13C NMR确证.初步生物测试表明,质量分数为0.01%时,3a～3o对白色念珠菌的抑菌率均达90%以上,具有很强的抑菌活性;对金黄色葡萄球菌、大肠杆菌的抑菌率达80%以上,具有较强的抑菌活性.     

Synthesis of Gingerenone C and 5-Hydroxy-1-(4'-hydroxy- 3'-methoxyphenyl)-7-(4"-hydroxyphenyl)-3-heptanone

The two diarylheptanoids (E)-1-(4'-hydroxy-3'-methoxyphenyl)-7-(4"-hydroxyphenyl) hept-4-en-3-one 1 (Gingerenone C) and (±)-5-hydroxy-1-(4'-hydroxy-3'-methoxyphenyl)-7-(4"-hydroxyphenyl)-3-heptanone 2 were synthesized from vanillin 3 and 4-hydroxybenzaldehyde 9.     

4,4′-[1,n-亚烷基双[(E)-2-(4-氧苯基)乙烯基]]双吡啶的光化学性质

通过E-[4-[2-(4-羟基苯基)乙烯基]吡啶与1,n-二溴烷烃亲核取代反应合成了4,4′-[1,n-亚烷基双[(E)-2-(4-氧苯基)乙烯基]]双吡啶[n=2(Ia),3(Ib),4(Ic),6(Id)].用元素分析、红外、紫外和质子核磁共振谱鉴定了Ia～Id的结构.将Ia～Id的稀溶液用中压汞灯和低压汞灯交替照射,发现其分子内光环加成反应的存在,并且随着亚烷基碳链的延长,反应速度加快.研究还发现锌离子可以与吡啶环上氮原子发生螯合作用使分子内光环加成反应加快.本文化合物荧光很弱,在较高浓度下有较强分子间激基缔合物荧光.