Synthesis of 2,5-bis[(3,4-ethylenedioxy)thien-2-yl]- 3-substituted thiophenes

[reaction: see text] Synthesis of 2,5-bis[(3,4-ethylenedioxy)thien-2-yl]-3-substituted thiophene monomers afforded compounds with blue emission characteristics and having a quantum yield of 3-5%. Cyclic voltammetry was employed to investigate the electrochemical behavior of the four monomers reported here. Polymer films were deposited by repeated potential cycling. These materials are considered for use in tailoring properties in optoelectronic device applications.     

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.     

Synthesis and mechanism of formation of novel 2,5-dihydro-2,5-diimino-3,4-di[(N,N-dimethylamino)methylideneamino]pyrroles and 5-amino-3,4-di[(N,N-dimethylamino)methylideneamino]-2H-2-iminopyrroles

Formation of 5-amino-3,4-di[(N,N-dimethylarnino)methylidenearnino]-2H-2-iminopyrroles 3 from the reaction of (Z)-N¹-(2-amino-1,2-dicyanovinyl)-N²-substituted-formamidines 1 with dimethylformamide diethyl acetal has been shown to occur by initial formation of (Z)-N¹-{l,2-dicyano-2-[N,N-dimethylamino)methylideneamino]vinyl}formamidines 8 (isolated), followed by base catalysed cyclisation and imi dazole ring opening by dimethyl amine. The kinetic product of the ring opening reaction is the 2,5-diimino2,5-dihydropyrrole derivatives 11, which have been isolated and characterized spectroscopically and by a single crystal X-ray analysis on the R = Ph derivative. In solution at room temperature the N-aryl derivatives undergo a rapid Dimroth rearrangement to give the thermodynamic ally more stable isomer 3 , but compound 11 (R = Me) is much more stable in solution.     

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…     

Synthesis and reactions of thiophene sulfides. Communication 40. An unusual reaction of 2,5-bis(methylthio)-3,4-bis(o-hydroxyphenyliminomethyl)thiophene

Conclusions In polar solvents (ethanol and chloroform), 2,5-bis(methylthio)-3,4-bis-(o-hydroxyphenyliminomethyl) thiophene undergoes intramolecular rearrangement to 2,5-bis(methylthio)-3-(2-benzoxazolyl)-4-(o-hydroxyphenylaminomethyl) thiophene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2750–2753, December, 1985.     

Polynaphthylimides based on isomeric 2,5-bis[(aminophenoxy)phenylen]-1,3,4-oxadiazoles

Polynaphthylimides containing 1,3,4-oxadiazole cycles in main chains of macromolecules are prepared via the interaction of isomeric 2,5-bis[(aminophenoxy)phenyl]-1,3,4-oxadiazoles with dianhydrides of naphthalene-1,4,5,8-tetracarboxylic acid and 1,3-bis(1,8-dicarboxynaphthoyl-4)benzene. These polymers are synthesized through high-temperature polycyclocondensation in N-methylpyrrolidone and molten phenol. The relationships between the solubility and thermal characteristics of polynaphthylimides and their structure are studied, and the optical properties of the polymers are estimated.     

Reactions of 1,2-di(2-thienyl)-3,4-bis[(2,4,6-tri-t-butylphenyl)phosphinidene]cyclobutene

Reactions of a sterically protected 1,2-di(2-thienyl)-3,4-bis[(2,4,6-tri-t-butylphenyl)phosphinidene]cyclobutene were investigated. The diphosphinidenecyclobutene reacted with elemental sulfur or transition metal reagents to form a thiaphosphirane derivative or the corresponding transition metal complexes, respectively. Reactions of the di(2-thienyl)diphosphinidenecyclobutene with butyllithium followed by treatment with electrophiles afforded functionalized di(2-thienyl)diphosphinidenecyclobutene derivatives.     

2,5-二(2-羟乙氨基)-1,4-苯醌合成方法的改进

以对苯二酚和乙醇胺为原料,直接合成2,5-二(2-羟乙氨基)-1,4-苯醌,并对产物进行红外、紫外、质谱及核磁表征.采用正交设计法对实验条件进行优化,乙醇为溶剂,对苯二酚和乙醇胺物质的量比为1∶5,在50℃下,反应2h,最高产率达到72.8%.产物为针状晶体,纯度较高.