Synthesis of 2,5 -Bis(4-methyl-2-thienyl)thiophene and 2,5-Bis(4-methyl-2-thienyl)pyrrole

Syntheses of 2,5-bis(4-methyl-2-thienyl)thiophene 3 and 2,5-bis(4-methyl-2-thienyl)pyrrole 4 are described. The key step involves Stetter reaction between 4-methyl-2-thiophenecarboxaldehyde and divinyl sulfone. Cyclizaton of the resulting 1,4-bis-(4-methyl-2-thienyl)-1,4-butanedione 2 with Lawesson's reagent gives 2,5-bis(4-methyl-2-thienyl)thiophene 3, whereas condensation with ammonium acetate provides the 2,5-bis(4-methyl-2-thienyl)pyrrole 4.     

Synthesis and Crystal Structure of 2,5—Bis（morpholino）—3,4—bis（p—chlorophenyl）thiophene

1 INTRODUCTION -Thiocarbonylthioformamide synthesized in 1980[1, 2] is a class of stable and almost unexplored compounds[3]. We have reported the reaction of - thiocarbonylthioformamides in our previous paper[4]. Here, we will report a novel synthesis of 2 by the reaction of 1 and trimethyl phosphite in refluxing xylene. In order to determine the structure of 2, X- ray crystallographic study was carried out. 2 EXPERIMENTAL 2. 1 Preparation of the title compound Trimethyl phosph…     

One-Pot Synthesis of N-Boc-2, 5-bis(trimethylsilyl)pyrrolidine

Since Daly reported the structure of epibatidine and its potent analgesic activity in 19921, study on the synthesis of epibatidine and its derivatives and relationships between the structure and activity of epibatidine has received much attention2. During the course of our research for the synthesis of epibatidine derivatives, N-boc-2, 5-bis(trimethylsilyl)pyrrolidine 4 was used as the key intermediate to construct the skeleton of epibatidine via the 1, 3-dipolar cycloaddition (Scheme 1). Ac…     

1，3-二(三甲基硅基)-2-叔丁基锂与铁(Ⅱ)、钴(Ⅱ)、镍(Ⅱ)、钛(Ⅳ)的反应及结构

1，3-二(三甲基硅基)-2-叔丁基锂与氯化镍或四氯化钛反应合成了内消旋的1，3-二(三甲基硅基)-2-叔丁基偶联化合物(1)；与氯化钴和氯化亚铁反应分别生成了二配位的1，3-二(三甲基硅基)-2-叔丁基钴和铁配合物(2，3)。用NMR,元素分析和X-射线衍射对其单晶的结构进行了分析，结果表明：化合物1属三斜晶系；化合物2和3均属单斜晶系，配合物2中心钴为六配位畸变的八面体构型。配合物3与2结构相类似。     

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 ).     

Polyhydrazides based on 2,5-bis(4-carboxymethylene phenyl)-3,4-diphenyl thiophene

A series of polyhydrazides was synthesized from a novel dicarboxylic acid, 2,5-bis(4-carboxymethylene phenyl)-3,4-diphenyl thiophene (V) and or terephthalic acid and isophthaloyl or terephthaloyl dihydrazide by Yamazaki’s phosphorylation method using triphenyl phosphite as condensing agent. Polyhydrazides were characterized by IR spectroscopy solubility, viscosity, thermogravimetric analysis and X-ray diffraction studies.The polymers were obtained in quantitative yields. Polyhydrazides had viscosities in the range of 0.25-0.70 dL/g. The polymers derived from novel diacid (V) showed enhanced solubility than the polymers derived from terephthalic acid, which may be attributed to the presence to bulky pendant phenyl group and methylene spacer group in the polymer backbone. Polymers were soluble in most of the common aprotic polar solvents. Polyhydrazides showed considerable weight loss in the temperature range of 300-400 °C which is due to the cyclodehydration, leading to the formation of corresponding polyoxadiazoles. They showed T_max in between 500 and 600 °C which is essentially the decomposition of the polyoxadiazoles. X-ray diffraction studies showed that polyhydrazides were amorphous in nature.     

Photochromic Dihetarylethenes. 8. A Novel Route to the Synthesis of 3,4-Bis(2,5-dimethyl-3-thienyl)furan-2,5-dione as a Potential Photochrome

There is proposed, and in the case of 2,5-dimethylthiophene carried out, a novel route to the synthesis of 3,4-dithienylfuran-2,5-dione type photochromes. This is done in two stages, the first being a Friedel-Crafts reaction of the starting thiophene with the dichloride of squaric acid and the second is a Baeyer-Villiger oxidation of the 3,4-bis(2,5-dimethyl-3-thienyl)cyclobutenedione to give the target 3,4-bis(2,5-dimethyl-3-thienyl)furan-2,5-dione.     

Poly(2,5‐thienylene vinylene) in Nano Shapes by CVD Polymerization

Poly(2,5‐thienylene vinylene) (PTV), an insoluble conjugated polymer, can be readily prepared in various shapes of different nanodimensions by the chemical vapor deposition polymerization of 2,5‐bis(chloromethyl)thiophene. The bischloromethyl monomer in the vapor phase is activated at 600 °C. The activated monomer vapor is deposited at room temperature on the surface of various substrates to prepare polymeric films, fibers, tubes etc., which are then thermally converted into PTV. PTV thin films can be carbonized thermally to produce graphitic compositions that contain sulfur atoms. Electrical conductivities of FeCl‐doped PTV and carbonized films are reported.

     

Synthesis and characterization of sodium bis(trimethylstannyl) amide and bis(trimethylsilyl) bis(trimethylstannyl) -phospha-tetrazene

Sodium bis(trimethylstannyl)amide NaN(SnMe₃)₂, isolated by the reaction of trimethylstannyldiethylamine with sodium amide, reacts with tris(trimethylsilyl)hydrazino—dichloro-phosphine to form bis(trimethylsilyl)bis(trimethylstannyl)-2-phospha-2-tetrazene, (Me₃Si)₂N-N=P-N(SnMe₃)₂. Both the molecules have been isolated and characterized.     

Synthesis and properties of polyimides derived from 1,4-bis(4-aminophenoxy)2,5-di-tert-butylbenzene

Novel aromatic polyimides containing symmetric, bulky di-tert-butyl substituents unit were synthesized from 1,4-bis(4-aminophenoxy)2,5-di-tert-butylbenzene (BADTB) and various aromatic tetracarboxylic dianhydrides by the conventional two-stage procedure that included ring-opening polyaddition in a polar solvent such as N,N-dimethylacetamide to give poly(amic acid)s, followed by cyclodehydration to polyimides. The diamine was prepared through the nucleophilic displacement of 2,5-di-tert-butylhydroquinone with p-chloronitrobenzene in the presence of K₂CO₃, followed by catalytic reduction. Depending on the dianhydrides used, the poly(amic acid)s obtained had inherent viscosities of 0.83–1.88 dL g⁻¹. Most of the polyimides formed transparent, flexible, and tough films. Tensile strength and elongation at break of the BADTB-based polyimide films ranged from 68–93 MPa and 7–11%, respectively. The polyimide derived from 4,4′-hexafluoro-isopropylidenebisphathalic anhydride had better solubility than the other polyimides. These polyimides had glass transition temperatures between 242–298°C and 10% mass loss temperatures were recorded in the range of 481–520°C in nitrogen. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1527–1534, 1997     

Synthesis of 4-hetaryl-5,6-(2,5-dimethyl-3-thienyl)-2-phenyl-4h-thiazines and investigation of their photochromism

The polar [4+2] cycloaddition reaction of 1,2-bis(2,5-dimethyl-3-thienyl)acetylene with thiobenzamide and certain aldehydes of the thiophene and furan series catalyzed by boron trifluoride etherate gives the corresponding 4-hetaryl-5,6-di(2,5-dimethyl-3-thienyl)-2-phenyl-4H-1,3-thiazines. The photochromic properties of the products have been studied.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 100–106, January, 2005.     

Bis(trimethylsilyl)amide und -methanide des Yttriums — Molekülstrukturen von Tris(diethylether-O)lithium-(μ-chloro)-tris[bis(trimethylsilyl) methyl]yttriat,solvensfreiem Yttrium-tris[bis(trimethylsilyl)amid] sowie dem Bis(benzonitril)-Komplex

Bis(trimethylsilyl)amides and -methanides of Yttrium — Molecular Structures of Tris(diethylether-O)lithium-(μ-chloro)-tris[bis(trimethylsilyl)methyl]yttriate, solvent-free Yttrium Tris[bis(trimethylsilyl)amide] as well as the Bis(benzonitrile) Complex The reaction of yttrium(III) chloride with the three-fold molar amount of LiE(SiMe₃)₂ (E = N, CH) yields the corresponding yttrium derivatives. Yttrium tris-[bis(trimethylsilyl)amide] crystallizes in the space group P3 1c with a = 1 636,3(2), c = 849,3(2) pm, Z = 2. The yttrium atom is surrounded trigonal pyramidal by three nitrogen atoms with Y? N-bond lengths of 222 pm. Benzene molecules are incorporated parallel to the c-axes. The compound with E = CH crystallizes as a (Et₂O)₃LiCl-adduct in the monoclinic space group P2₁/n with a = 1 111,8(2), b = 1 865,2(6), c = 2 598,3(9) pm, β = 97,41(3)° and Z = 4. The reaction of yttrium tris[bis(trimethylsilyl)amide] with benzonitrile yields the bis(benzonitrile) complex, which crystallizes in the triclinic space group P1 with a = 1 173,7(2), b = 1 210,3(2), c = 1 912,4(3) pm, α = 94,37(1), β = 103,39(1), γ = 117,24(1)° and Z = 2. The amido ligands are in equatorial, the benzonitrile molecules in axial positions.     

Strontium- und Barium-bis[N,N′ -bis(trimethylsilyl)benzamidinate] aus der Additionsreaktion der Erdalkalimetall-bis[bis(trimethylsilyl)amide] mit Benzonitril

Strontium and Barium Bis[N,N′-bis(trimethylsilyl)benzamidinates] from the Addition Reaction of the Alkaline Earth Metal Bis[bis(trimethylsilyl)amides] and Benzonitrile The reaction of strontium bis[bis trimethylsilyl)amide] with benzonitrile yields strontium bis[N,N′- bis(trimethylsilyl)benzamidinate] · 2THF, which crystallizes in the orthorhombic space group Pbcn (a = 1845.4(3); b = 131 1,3(2); c = 1838,(3) pm; Z = 4). During the similar reaction of barium bis[bis(trimethylsilyl)amide] with benzonitrile the benzonitrile adduct barium bis[N,N′-bis(trimethylsilyl)benzamidinate] · 2 THF · benzonitrile is formed. After the addition of diphenylacetylene to the strontium di(benzamidinate) in diglyme a clathrate of the composition strontium bis[N,N′-bis(trimethylsilyl)benzamidinate] · diglyme · diphenylacetylene could be isolated; the spectroscopic data as well as the X-ray structure (monoclinic, C2/c, a = 1492.2(2); b = 1539.1(2); c = 2337.8(3)pm; Z = 4) confirm the isolated appearance of the acetylene molecule without interaction to the metal center in solution and in the solid state, respectively.     

Vinyl tris(trimethylsilyl)silanes: substrates for Hiyama coupling

The oxidative treatment of vinyl tris(trimethylsilyl)silanes with hydrogen peroxide in aqueous sodium hydroxide in tetrahydrofuran generates reactive silanol or siloxane species that undergo Pd-catalyzed cross-couplings with aryl, heterocyclic, and alkenyl halides in the presence of Pd(PPh₃)₄ and tetrabutylammonium fluoride. Hydrogen peroxide and base are necessary for the coupling to occur while activation of the silanes with fluoride is not required. The conjugated and unconjugated tris(trimethylsilyl)silanes serve as good cross-coupling substrates. The (E)-silanes undergo coupling with retention of stereochemistry while coupling of (Z)-silanes occurred with lower stereoselectivity to produce an E/Z mixture of products.     

聚（3，4-二氯）噻吩的制备及表征

以四氯噻吩为原料,采用化学合成法制备了聚（3,4-二氯）噻吩．对影响合成材料结构规整度的溶剂极性进行了初步探讨,并采用元素分析、红外光谱、^13C NMR核磁谱等对目标产物进行了表征．结果表明,当采用极性较低的乙二醇二甲醚作溶剂时,可得到规整度较高的目标产物．     

2,5-二(2-氨基乙氧甲基)噻吩合成及抑菌活性

噻吩烷基胺及其衍生物对疟疾、麻风、真菌、病毒和某些肿瘤均有较强的药理活性[1～ 2 ] ,因此合成和开发这类新物质具有重要的意义。以前 ,由 2 噻吩甲醛合成的噻吩类衍生物药物较多[3] ,但对噻吩双取代衍生物的合成研究还未引起重视。因此 ,为了探索这类化合物的性质和抑菌效果。我们合成了未见文献报道的 2 ,5 二 ( 2 氨基乙氧甲基 )噻吩 ,通过多种测试手段 ,确定了它的组成结构 ,其合成路线如下 :1　实验部分1 1　仪器与试剂Ｎｉｃｏｌｅｔ1 70Ｓ红外光谱仪 (ＫＢｒ压片 ) ,ＰＥ 2 4 0Ｃ型元素分析仪 ,ＥＭ 360 60ＭＨｚ核磁共振仪。…     

聚丙烯酸[2,5-双(对甲氧基苯甲酰氧基)苄酯]及聚甲基丙烯酸[2,5-双(对甲氧基苯甲酰氧基)苄酯]的合成

周其凤等曾报道聚丙烯酸［２,５－双（对甲氧基苯甲酰氧基）节酯］［１］和聚甲基丙烯酸［２,５－双（对甲氧基苯甲酰氧基）苄酯］［２］的合成．但后来的研究发现,在合成单体的条件下出现的一种未见报道的异常反应［３］使产物成分复杂化,因此当时报道的聚合物可能不是聚丙烯酸［２,５－双－（对甲氧基苯甲酰氧基）苄酯］或聚甲基丙烯酸［２,５－双（对甲氧基苯甲酰氧基）苄酯］,而可能是共聚物．针对这一问题,我们重新设计了合成路线以避免发生上述副反应,成功地合成了丙烯酸或ａ－甲基丙烯酸［２,５－双－（对甲氧基苯甲酰氧基…     

2,5-双(乙炔基二茂铁)噻吩/钨磷杂多酸纳米杂化LB膜的制备与光电性质研究

以含有共轭大π键的2,5-双(乙炔基二茂铁)噻吩(BFET)和二甲基双十八烷基铵(DMDOA)与Keggin结构和Dawson结构钨磷杂多酸做成膜材料, 用LB技术组装了两种新型无机-有机杂化LB膜. 用π-A曲线、UV-vis吸收光谱、原子力显微镜(AFM)、扫描隧道显微镜(STM)、荧光光谱和表面光电压谱(SPS)对标题LB膜的成膜性能、结构及光电性质进行了研究, 发现标题杂化LB膜的粒子具有纳米尺寸, 在可见光区有较强的光电压响应, 在电压为±2.0 V时, 隧道电流值达到±100 nA.