Synthesis of novel 1-aryl-substituted 8-methoxynaphthalenes and their tendency for atropisomerization

Novel 1-aryl-substituted 8-methoxynaphthalenes were conveniently prepared by using Suzuki-Miyaura cross-coupling as a key reaction. Chemical transformations of the coupled products gave a variety of biaryls bearing various functional groups. The optical behavior of the separated enantiomers of these derivatives was also investigated by HPLC analysis. The optical resolution and determination of absolute configuration of novel binaphtyl derivative were also described. These new compounds may have some potential as mono- or bidentate ligands for metal-catalyzed chemical transformations including asymmetric induction.     

Design,synthesis and biological evaluation of novel N1,N8-bis(((4-((5-aryl-1,3,4-oxadiazol-2-yl)methoxy)phenyl)amino)oxy)-1-naphthamide derivatives

A new series of 1,8-bis(4-((5-phenyl-1,3,4-oxadiazol-2-yl) methoxy)-substituted aryl) naphthalene-1,8-dicarboxamide derivatives (6a–j) were synthesized in the presence of POCl₃ and obtained good yields. All the synthesized novel compounds were characterized by IR, ¹H NMR, ¹³C NMR, HRMS spectroscopic data and elemental analysis. All the synthesized compounds evaluated for their antibacterial and antifungal activities. The antibacterial activity screened against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli and used standard reference drug ciprofloxacin. The antifungal activity screened against two pathogenic fungal strains Aspergillus niger and Candida albicans used a reference standard drug Voriconazole. All these compounds (6a–j) demonstrate good antibacterial and antifungal activity. Among them, compounds 6h and 6c show highest antibacterial and antifungal activity.     

Synthesis of Novel Pyrrolo[1′,5′‐a]‐1,8‐naphthyridine Derivatives through a Facile One‐Pot Process

Novel pyrrolo[1′,5′‐a]‐1,8‐naphthyridine compounds have been synthesized through a facile one‐pot process by the reaction of the corresponding 1,8‐naphthyridines with aliphatic anhydride. The structures were established by spectroscopic data. Further X‐ray crystal analysis of 4′‐acetyl‐7‐methyl‐pyrrolo[1′,5′‐a]‐1,8‐naphthyridine (1) identifies its intriguing molecular structure and reveals the strong π‐π stacking.     

Synthesis and special characterization through X-ray analysis of 1,8-dioxooctahydroxanthenes

Pyran moiety containing heterocyclic compounds have the capability for binding to either side to cyclohex-2-enone rings and to form xanthene derivatives (1,8-dioxooctahydroxanthenes also known as xanthenodiones). These xanthene derivatives display a wide range of biological activities and find applications in laser technologies and photodynamic therapy. This paper describes the preparation, X-ray structural analysis, and theoretical investigation of a series of 1,8-dioxooctahydroxanthenes. The compounds were synthesized via Knoevenagel condensation between different aldehydes and β-diketones. The reactions were performed free of solvents and the 1,8-dioxooctahydroxanthenes were obtained in good yields (70−92%). All the compounds were fully characterized by NMR and IR spectroscopy as well as mass spectrometry. Among the synthesized compounds, seven had their crystal structures elucidated for the first time. In all the new crystal structures, the three fused rings did form an almost completely planar xanthenodione core, except for the side rings that adopt half-chair conformation with both carbons at the flaps oriented toward to the aromatic substituent, or with one of the two carbons pointing opposite to the substituent. Another conformational difference among the new compounds investigated by X-ray diffraction resides in the rotation around the bond axis connecting the xanthenodione core to its aromatic substituent. It was found that different bent levels resulted from weak intermolecular contact patterns. In addition, theoretical calculations for single molecule and dimmers have provided insights into the balance between intramolecular and intermolecular forces driving both conformational features.     

Solvent-free synthesis of polyhydroquinoline and 1,8-dioxodecahydroacridine derivatives through the Hantzsch reaction catalyzed by a natural organic acid: A green method

Solvent-free and high yielding one-pot synthesis of 1,8-dioxodecahydroacridine and polyhydroquinoline derivatives have been described through Hantzsch condensation of various aldehydes, ammonium acetate with cyclic 1,3-dicarbonyl compounds and ethyl acetoacetate in a very simple, efficient, and environmentally benign method using ascorbic acid as a nontoxic organocatalyst.     

Synthesis and fluorescence study of 3-aminoalkylamidonapthalimides

A new series of fluorescent 3-aminoalkylamidonapthalimides were synthesized starting form 1,8-naphthalic anhydride. The structure of these compounds was characterized by ¹H NMR, ¹³C NMR, IR and Mass spectral analysis. The solvent effect on ¹H and ¹³C NMR of these compounds was studied in CDCl₃, CDCl₃:DMSO-d₆ (7:3, v/v) and DMSO-d₆. NMR chemical shift of the ortho and para protons and meta carbons of naphthalene ring showed maximum variation on moving from CDCl₃ to DMSO-d₆. In CDCl₃ solvent naphthalene ring may exist in slightly puckered form while in DMSO-d₆ it attains maximum planar configuration. Fluorescent properties of the title compounds and their precursors were investigated in different solvents like chloroform, ethanol, acetonitrile, acetone, DMSO and water. 3-Aminoalkylamidonapthalimides exhibited improved fluorescence than their precursors. Cyclic amino derivatives yielded higher fluorescence quantum efficiency in protic solvents, ethanol and water. Acylic amino derivatives yielded high fluorescence quantum efficiency in chloroform solvent. The maximum fluorescence quantum yield up to 0.14 was found for butyl amine derivative in chloroform solvent. In general proton accepting nucleophilic solvents like acetone and DMSO quenched the fluorescence.     

A synthesis and biological screening of newly substituted 9-methyl-6-aryl-[1,2,4]triazolo[4,3-a][1,8]naphthyridines using chloranil

An effective, mild, and convenient method for the synthesis of 10 new substituted 9-methyl-6-aryl-[1,2,4]triazolo[4,3-a][1,8]naphthyridines (5a–j) by the oxidation of the corresponding 2-(2-ethylidenehydrazinyl)-3-aryl-1,8-naphthyridines (4a–j) using chloranil under conventional method has been described. The structures of synthesized compounds (5a–j) were established on the basis of their elemental analysis and spectral (IR, Mass, ¹³C- and¹H-NMR) data. The new compounds were synthesized with the objective of studying their antibacterial activity. The reaction will be characterized by easy workup, good efficacy, simple purification of the products, and availability of catalyst.     

One-Pot Synthesis of Biologically Important Spiro-2-amino-4H-pyrans,Spiroacenaphthylenes, and Spirooxindoles Using DBU as a Green and Recyclable Catalyst in Aqueous Medium

We have reported DBU-catalyzed one-pot synthesis of biologically and pharmacologically important spiropyrans from condensation of malononitrile/ethyl cyanoacetate, 1,3-dicarbonyl compounds, and ninhydrin/acenaphthequinone/istain in good yields. This new protocol employing DBU, which is a green, recyclable, and inexpensive catalyst, offers advantages such as mild reaction conditions, short reaction times, and easy isolation of products. The structures have been confirmed by x-ray analysis.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Infrared Absorption Studies of Some New 1,8-Naphthalimides

Some new 4-nitro- and 4-allylamino-N-phenyl-1,8-naphthalimides comprising different substituents in the phenyl ring have been studied by infrared absorption spectroscopy. The effect of the nature of the substituents upon the vibration frequencies of the carbonyl groups has been discussed.     

Influence of steric and electronic effects of substituents on the molecular structures and conformational flexibility of 1,8-naphthalenedicarboximides

A series of 1,8-naphthalenedicarboximide derivatives containing substituents of different steric and electronic nature were studied by X-ray diffraction analysis.Ab initio quantumchemical calculations in the HF/3–21G approximation demonstrated the high conformational flexibility of the imide tetrahydro ring in the molecules of these compounds. The electronic nature of the substituents has no effect on the geometry and conformational flexibility of naphthalenedicarboximides due to weak conjugation between the imide and naphthalene fragments in the molecules. However, the steric effects of the bulky substituents noticeably affect the equilibrium geometry of the imide ring by increasing its conformational flexibility. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 68–73, January, 2000.     

Influence of steric and electronic effects of substituents on the molecular structures and conformational flexibility of 1,8-naphthalenedicarboximides

A series of 1,8-naphthalenedicarboximide derivatives containing substituents of different steric and electronic nature were studied by X-ray diffraction analysis.Ab initio quantumchemical calculations in the HF/3–21G approximation demonstrated the high conformational flexibility of the imide tetrahydro ring in the molecules of these compounds. The electronic nature of the substituents has no effect on the geometry and conformational flexibility of naphthalenedicarboximides due to weak conjugation between the imide and naphthalene fragments in the molecules. However, the steric effects of the bulky substituents noticeably affect the equilibrium geometry of the imide ring by increasing its conformational flexibility. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 68–73, January, 2000.     

3,4-二氟硫酚酯类液晶化合物的合成及性能

合成了一系列新的3，4-二氟硫酚酯类液晶化合物，收率64．2％～74．9％。其结构经IR和1H NMR确认。并研究了合成过程中溶剂对酰化反应定位效应的影响。热性能测试表明，该类化合物液晶相变区间较宽并具有较高的清亮点。     

Thermal characterization of tetramethylphosphonium perchlorate, -nitrate and -picrate

Tetramethylphosphonium perchlorate, -nitrate and -picrate have been characterized thermally employing differential thermal analysis and thermogravimetric techniques. The thermal stability of these compounds is found to be in the order, perchlorate>nitrate>picrate. A similar trend is stability has been obserbed in the case of the corresponding ammonium compounds. These observations have been explained in terms of the dissociation of these salts prior to their decomposition. Explosion sensitiveness of these compounds has been determined by explosion delay measurements which also seem to indicate the same order of relative stability. The ammonium compounds appear to be more stable than their phosphonium counterparts.     

含三唑二硫代膦酸酯类衍生物的研究

合成了四种含三唑二硫代膦酸酯衍生物；通过红外光谱、核磁共振氢谱、元素分析确证了化合物的结构，生物初筛结果表明，所有化合物均有一定的杀菌、除草和植物生长调节活性。     

铌取代型钨硅杂多酸盐的合成及抗病毒活性研究

杂多化合物因具有独特的结构和优异的抗病毒活性^[1,2],近年来受到普遍重视,但研究的热点主要集中在抗艾滋病毒(HIV)、疱疹病毒(HSV)、抗肿瘤等方面^[3,4],而忽视了对植物病毒防治的研究。     

芳氧乙酸－3，3－二甲基－2－羰基丁酯衍生物的合成与生物活性

芳氧乙酸－３，３－二甲基－２－羰基丁酯衍生物的合成与生物活性史延年，李士明，方建新（南开大学元素有机化学研究所，天津，３０００７１）关键词芳氧乙酸酯，合成，生物活性芳氧乙酸及其酯类衍生物具有良好的生物活性．作者曾以苯氧乙酸类化合物为母体，合成了一系列...     

N-亚硝基化合物结构-致癌活性的相关性研究

Ｎ－亚硝基化合物结构－致癌活性的相关性研究许禄,姚瑜元（中国科学院长春应用化学研究所应用谱学开放实验室,长春,１３００２２）关键词Ｎ－亚硝基化合物,半经验量化方法,构效关系目前已发现的Ｎ－亚硝基化合物约３００种中多数具有致癌活性。化学家和生物学家对该...     

Novel synthesis of substituted N-(3-aryl-1,8-naphthyridin-2-yl) and N,N′-bis(3-aryl-1,8-naphthyridin-2-yl)benzene-1,4-diamines and 2-(4-((3-aryl-1,8-naphthyridin-2-yl)amino)phenyl)isoindoline-1,3-diones and their biological evaluation

A straightforward and highly efficient series of new substituted 3-aryl-1,8-naphthyridine derivatives 3a–e, 4a–e, and 6a–e were synthesized. Condensation dissimilar quantities of 2-chloro-3-aryl-1,8-naphthyridine 1a–e with benzene-1,4-diamine 2 and sodium ethoxide refluxing in ethanol solvent yielded the compounds 3a–e and 4a–e. The 2-(4-((3-aryl-1,8-naphthyridin-2-yl)amino)phenyl)isoindoline-1,3-diones 6a–e were obtained by treatment of compounds 3a–e with phthalic anhydride 5 in refluxing N,N-dimethylformamide is described. All synthesized compounds evaluated for their antimicrobial activity. The structures of the compounds have been proven on the established of spectral (IR, ¹H NMR, and ¹³C NMR) data and elemental analyses. The reaction will be characterized by good efficacy, easy workup, simple purification of the products, and availability of catalyst.     

Synthesis of 1,3-diazapyrenes and 1,3,7-triazapyrenes by the reaction of 1,8-naphthalenediamine with triazine in the presence of carbonyl compounds or benzonitrile in polyphosphoric acid

A novel three-component synthesis has been developed for 1,3-diazapyrenes based on the reaction of 1,8-naphthalenediamine with triazine and carbonyl compounds in polyphosphoric acid (PPA). The use of benzonitrile in place of the carbonyl compounds in this reaction gives 6-phenyl-1,3,7-triazapyrenes. Dedicated to one of the best Russian chemists A. F. Pozharskii on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1694–1698, November, 2008.     

几种硝基苯甲酸卟啉酯类化合物的合成

卟啉化合物在模拟光合作用、探索高效利用太阳能等方面具有重要的理论意义和应用前景^[1]。近年来,人们对共价键相连的“卟啉-醌”类化合物研究较多,而关于“卟啉-硝基”类化合物的报道则较少,硝基具有强吸电子等特性,它作为“卟啉-硝基”类化合物的电子受体有利于分子内发生电子传递,可望是光合作用机理研究中的一类较好的模型化合物。为此,我们设计合成了具有不同性质的供体和不同位置的受体的8种新硝基苯甲酸及苯甲酸卟啉酯类化合物,它们的结构已分别通过质谱、核磁、红外、紫外可见光谱以及元素分析确证,结果见表1、2。