Stereoselective Synthesis and Diels-Alder Reactions of (Z)- and (E)-1,2-bis(Phenylthio)-1,3-Butadiene

Bromination of 3-phenylthio-2-sulfolene (2) with N-bromosuccinimide gave 2-bromo-3-phenylthio-2-sulfolene (3) which was converted mainly to 2,3-bis(phenylthio)-2-sulfolene (4) by treatment with sodium phenylthiolate. Thermal desulfonylation of 4 at different temperatures in the presence of a base (DBU) yielded stereoselectively the (Z)- and (E)-1,2-bis(phenylthio)-1,3-butadiene (6). These two geometric isomers could be thermally interconverted. The Diels-Alder reactions of 6 were also investigated. Only the (Z)-diene 6a could undergo the Diels-Alder reaction; the (E)-diene 6b was in situ converted to the Z isomer before undergoing (he Diels-Alder reaction. The reaction of 6a with N-phenylmaleimide gave the cycloaddition product 7 with complete endo selectivity, but under daylight or during chromatography it readily underwent a thioallylic rearrangement to yield 8 with inversion of configuration. The cycloaddition of 6a with methyl acrylate proceeded regiospecifically, but generating a mixture of endo and exo isomers. The endo/exo ratio could be increased by using ZnCl₂ as the catalyst.     

2-乙酰噻吩及其新型席夫碱的合成

以磷钨酸为催化剂,噻吩和乙酸酐反应合成了2-乙酰噻吩(1,收率83.5%);1与不同结构的酰肼反应合成了四种新型席夫碱(2a～2d),收率90%～95%,其结构经UV,~1H NMR,~(13)C NMR,IR及元素分析表征.优化了合成1和2的反应条件.     

4-(7-甲氧基-2,2-二甲基-2,3-二氢苯并呋喃-5-基)-2-芳氨基噻唑的合成、晶体结构与杀虫活性

以2-(2-甲基烯丙氧基)苯酚为原料, 经Claisen重排、呋喃环化、醚化、Friedel-Crafts乙酰化、α-溴代和噻唑环化等反应合成了22种4-(7-甲氧基-2,2-二甲基-2,3-二氢苯并呋喃-5-基)-2-芳氨基噻唑化合物. 化合物的结构经质谱、1H NMR和元素分析等确证. 采用单晶X射线衍射仪测定了化合物7j的晶体结构, 该晶体属于单斜晶系, 空间群为C2/c, 晶胞参数a=2.21140(12) nm, b=0.87602(5) nm, c=2.13911(12) nm, β=115.5380(10)°; V=3.7391(4) nm3, Z=8, Dc=1.375 g/cm3, F(000)=1616, S=1.046, μ=0.333 mm-1, 最终偏差因子R1=0.0390, wR2=0.1079. 杀虫活性实验结果表明, 化合物7a, 7b, 7h和7t在浓度为500 mg/L时对蚕豆蚜死亡率分别为95.12%, 62.60%, 57.53%和59.06%.     

Synthesis,structure, spectroscopic,and DNA binding properties of Co(III) and Ni(II) complexes with ((E)-2-(amino((pyridin-2-ylmethylene)amino)methylene)maleonitrile)

Two new complexes, [Co(L)₂]Cl·(MeOH)₂ (1) and [Ni(L)₂]₄·EtOH (2) (L?=?(E)-2-(amino((pyridin-2-ylmethylene)amino)methylene)maleonitrile), were synthesized and characterized by X-ray crystallography, IR, UV, and fluorescence spectroscopy. According to X-ray crystallographic studies, each metal was six-coordinate with six nitrogens from two ligands. Both complexes form two-dimensional supramolecular networks via hydrogen bonding and π–π interactions. Ultraviolet and visible spectra showed that absorptions arise from π–π ^?, MLCT, and d–d electron transitions. Fluorescence spectroscopy revealed moderate intercalative binding of these two complexes with EB–DNA, with apparent binding constant (K _app) values of 9.14?×?10⁵ and 3.20?×?10^5?M^?1 for Co(III) and Ni(II) complexes, respectively. UV–visible absorption spectra showed that the absorption of DNA at 260?nm was quenched for 2 but quenched then improved for 1 with addition of complexes, tentatively attributed to the effect of the combined intercalative binding and electrostatic interaction for 1.     

Synthesis and Crystal Structure of 4-Chloro-N- （2-（2-nitrophenyl）acetoxy）-N-（m-tolyl）benzamide

The new title compound 4-chloro-N-(2-(2-nitrophenyl)acetoxy)-N-(m-tolyl)benzamide(C22H17ClN2O5, Mr = 424.82) has been synthesized via the reaction of 4-chloro-N-hydroxy-N-(m-tolyl)benzamide with 2-(2-nitrophenyl)acetyl chloride. The structure of the product was confirmed by 1H NMR, 13 C NMR, IR, HRMS(ESI) and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/c with a = 13.0269(10), b = 6.7251(6), c = 23.9313(16) , β = 99.931(6)o, V = 2065.1(3) 3, Z = 4, Dc = 1.366 g/cm3, F(000) = 880, μ = 0.221 mm-1, the final R = 0.0600 and wR = 0.1754 for 1981 observed reflections(I 2σ(I)). X-ray analysis indicates that the chloro-phenyl ring(C(10)~C(15)) and the methyl-substituted benzene ring(C(16)~C(21)) are not coplanar with the nitro-substituted benzene ring(C(1)~C(6)), with the dihedral angle to be 70.78° and 63.72°, respectively. Hydrogen bonds C(2)–H(2)···O(2) and C(7)–H(7B)···O(5) are observed.     

Synthesis, structural characterization and electrochemical studies of new macrocyclic Schiff base containing pyridine head and its metal complexes

A new macrocyclic ligand, 1,3,5-triaza-2,4:7,8:13,14-tribenzo-9,12-dioksa-cyclopentadeca-1,5-diene was synthesized by reaction of 2,6-diaminopyridine and 1,2-bis(2-carboxyaldehyde phenoxy)ethane. Then, its Cu(II), Ni(II), Pb(II), Co(III) and La(III) complexes were synthesized by the template effect by the reaction of 2,6-diaminopyridine and 1,2-bis(2-carboxyaldehyde phenoxy)ethane and Cu(NO₃)₂ · 3H₂O, Ni(NO₃)₂ · 6H₂O, Pb(NO₃)₂, Co(NO₃)₂ · 6H₂O, La(NO₃)₃ · 6H₂O, respectively. The ligand and its metal complexes have been characterized by elemental analysis, IR, ¹H and ¹³C NMR, UV-Vis spectra, magnetic susceptibility, thermal gravimetric analysis, conductivity measurements, mass spectra, and cyclic voltammetry. All complexes are diamagnetic and Cu(II) complex is binuclear. The Co(II) was oxidized to Co(III). The comparative electrochemical studies show that the nickel complex exhibited a quasi-reversible one-electron reduction process, while copper and cobalt complexes gave irreversible reduction processes in DMSO solution.     

Synthesis of substituted 1,2-di(alkylsulfonyl)indolizines. Molecular and crystal structure of 3-(4-fluorobenzoyl)-6-methyl-1,2-di(propylsulfonyl)indolizine

The reactions of substituted pyridinium salts with E-1,2-di(alkylsulfonyl)-1,2-dichloroethenes proceed regiospecifically. Heating of these reagents in chloroform in the presence of a threefold excess of Et₃N affords substituted 1,2-di(alkylsulfonyl)indolizines in high yields. The structures of the reaction products were confirmed by physicochemical methods, including X-ray diffraction. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1205–1209, May, 2005.     

A facile synthesis of novel unsymmetrical N-(4-oxo-2-phenyl-3(4H)-quinazolinoyl)-N-(aryl)acetamidines

<正>A series of novel unsymmetrical N-(4-oxo-2-phenyl-3(4H)-quinazolinoyl)-N-(aryl) acetamidines was synthesized by reacting ethyl(1H)-N-(4-oxo-2-phenylquinazolin-3(4H)-y1)ethanimidoate(2) and suitable reactive aromatic amines.Structures' determination of the synthesized compounds was carried out using spectroscopic techniques including IR,~1H NMR,and mass spectrometry. Structural effects on reactivity were also studied.     

低价钛试剂促进下2-(2-硝基苯基)咪唑与席夫碱的反应

在低价钛试剂作用下,以四氢呋喃为溶剂,研究了2-(2-硝基苯基)咪唑与席夫碱的分子间还原偶联反应.结果发现席夫碱中C-N键的断裂优于其与硝基的偶联成环,生成了5,6-二氢化咪唑并[1,2-c]喹唑啉.     

Synthesis, Crystal Structure and Antibacterial Activity of 1-（（2-Chloroquinolin-3-yl）-methyl）-pyridin-2（1H）-one

On the basis of the interesting structures and biological activities exhibited by several heterocyclic systems possessing the pyridone nucleus such as mappcine and camptothecin, we have planed to design the synthesis, crystal studies and antibacterial activity of the new 1-((2- chloroquinolin-3yl)-methyl)-pyridine-2(1H)-one building block. An X-ray analysis has provided valuable insight into the effect of steric factors on the three-dimensional shape of this compound which serves as a useful advanced intermediate in the synthesis of these biologically active molecules. A multistep synthesis of camptothecin (5) has been designed by retrosynthetic analysis as part of an ongoing program on lead anticancer drug.     

Synthesis and Bioassay of Ethyl-2- (2-((Diethoxyphosphoryl) (Aryl) Methylamino)Thiazol-4-Yl)-2-(Methoxyimino)Acetates

Abstract

A simple, efficient, and environmentally benign methodology has been accomplished for the synthesis of α-aminophosphonates by one-pot three-component reaction of ethyl-2-amino-α-(methoxy-imino)-4-thiazoleacetate, aldehydes, and diethylphosphite by using Amberlyst-15 as catalyst at room temperature under solvent-free conditions. Their chemical structures were characterized by infrared (IR), NMR (¹H, ¹³C & ³¹P), mass spectral, and elemental analysis. All the title compounds were screened for radical-scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitic oxide (NO), and hydrogen peroxide (H₂O₂) methods.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and figures.     

Triphenylphosphine-Mediated Eco-Friendly Synthesis of (Z)-Diisopropyl-2-(Cyano(Aryl)Methylene)Hydrazine-1,1-Dicarboxylates Using Potassium Hexacyanoferrate(II) as a Cyanide Source

Abstract

A triphenylphosphine-mediated synthetic method for (Z)-diisopropyl-2-(cyano (aryl)methylene)hydrazine-1,1-dicarboxylates via one-pot three-component reactions using potassium hexacyanoferrate(II) as a cyanide source was described. This protocol has advantages of no use of strong toxic cyanating agents, high yield, and simple work-up procedure.     

Synthesis,Crystal Structure and Antitumor Activity of 4-(tert-butyl)-5-(1H-1,2,4-triazol-1-yl)-N-(2-hydroxy-3,5-diiodinebenzyl)-thiazol-2-amine

The title compound, 4-(tert-butyl)-5-(1H-1,2,4-triazol-1-yl)-N-(2-hydroxy-3,5-diiodinebenzyl)thiazol-2-amine, was synthesized via the reduction of 4-(tert-butyl)-5-(1H-1,2,4-triazol-1-yl)-N-benzylidene-thiazol-2-amine with Na BH4, and its crystal structure was determined by single-crystal X-ray diffraction. The compound crystallizes in monoclinic system, space group P21/c with a = 7.91944(19), b = 10.5250(3), c = 24.4985(6) , Z = 4, V = 2041.66(9) 3, Mr = 599.22, Dc = 1.949 Mg/m3, S = 1.120, μ = 3.203 mm-1, F(000) = 1152, the final R = 0.0283 and wR = 0.0592 for 3490 observed reflections(Ⅰ 2σ(Ⅰ)). X-ray analysis displays that the crystal water takes part in three intermolecular hydrogen bonds of O(2)–H(2A)···O(1), O(2)–H(2B)···N(1) and N(5)–H(5)···O(2), and an octatomic ring is formed via intramolecular hydrogen bond of O(1)–H(1A)···N(4). Furthermore, the Ⅰ···Ⅰ contacts are involved in stabilizing the overall three-dimensional network structure. The preliminary biological test shows the title compound has good antitumor activity with the IC50 value of 26 μM against the Hela cell line.     

新型荧光试剂N-2-噻唑基水杨醛亚胺Schiff碱的合成及荧光性质

合成了１０种新型荧光试剂Ｎ－２－噻唑基水杨醛亚胺Ｓｃｈｉｆ碱,通过元素分析,ＩＲ,１ＨＮＭＲ和ＵＶ－ｖｉｓ光谱进行了结构表征,并且测定了试剂的荧光光谱,微量的二价碱土金属离子对试剂的荧光有一定的熄灭作用     

2-氨基-5-(4-吡啶基)-1, 3, 4-噻二唑Schiff碱的合成及其生物活性

2-氨基-5-(4-吡啶基)-1;3;4-噻二唑Schiff碱的合成及其生物活性;噻二唑;Schiff碱;合成;生长素;细胞分裂素     

Synthesis and Characterization of Some New Organoantimony(III) Derivatives of N,S Donor Bifunctional Tetradentate Schiff Bases

Reactions of triphenylantimony(III) with the corresponding Schiff bases in equimolar ratios yield the phenylantimony(III) derivatives, PhSb[RC(NC 6 H 4 S)CH 2 (NC 6 H 4 S)CCOOCH 3 ] (R = C 6 H 5 , 4-ClC 6 H 4 , 4-BrC 6 H 4 , and 4-CH 3 C 6 H 4 ). These derivatives have been characterized by elemental analyses, molecular weight measurements, and IR as well as NMR ( 1 H and 13 C) spectral studies which reveal a five coordination around the central antimony atom.     

A novel entry to xanthones by an intramolecular Diels-Alder reaction involving 2-(1,2-dichlorovinyloxy) aryl dienones

A wide array of synthetic methods are described in the literature for the preparation of xanthones—a prominent class of tricyclic molecules that occur widely in nature. Majority of these reported methods involve linking the two aromatic rings and forming the central pyrone ring using a variety of classical and non-classical cyclization strategies. In a conceptually different approach, we describe here a new xanthone synthesis wherein both the pyrone and the second aromatic rings were forged in a single step by an intramolecular cycloaddition reaction involving 2-(1,2-dichlorovinyloxy) aryldienones.     

1,2-二(2-芳基-1,3,4-三唑-5-硫代)乙烷和1,3-二(2-芳基-1,3,4-三唑-5-硫代)丙烷的合成研究

以２－芳基－５－巯基－１，３，４－三唑为原料，在稀碱存在下与二卤代烷反应合成了１０个新的标题化合物。经元素分析确定了化合物的组成，红外光谱、核磁共振氢谱和质谱确证了其结构。初步考查了它们的生物活性。     

The Synthesis of 2-(Arylthio)arylcyanamides via Copper-Catalyzed Domino Intermolecular C-S Cross-Coupling Reaction of 2-Aminobenzothiazoles with Aryl Iodides

Abstract

A series of 2-(arylthio)arylcyanamide derivatives were obtained in excellent yields via a copper-catalyzed domino C–S cross-coupling of 2-aminobenzothiazoles with aryl iodides. This reaction occurred via an intermolecular C–S bond formation, associated with C–S bond cleavage, followed by an intermolecular S-arylation under ligand-free conditions. Their structures were unambiguously determined by the analytic tools, such as HRMS, ¹H, and ¹³C NMR analysis.     

Synthesis of 2- and 3-pyridinyl(aryl)methanones

A procedure was developed for the preparation of 2- and 3-pyridinyl(aryl)methanones by the reactions of aryllithium with methyl pyridinecarboxylate and methyl esters of substituted phenylcarboxylic acids.