首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Synthesis and Transport Investigations of Dioxapolyazacalix[4]arenes and Triazino Crown Ethers Synthesis and characterisation of new dioxapolyazacalix[4]arenes 5a–c and triazino crown ethers 9a–i are described. The structures and conformations of these novel macrocyclic ring systems have been investigated by various NMR methods. Transports of metal ions across a liquid membrane are also reported.  相似文献   

2.
Liquid Crystalline Hydroquinone Bis-[trans-4-n-Alkylcyclohexane]-carboxylates The synthesis of methyl-, ethyl-, chloro-, bromo-, cyano- and methoxy-substituted esters of hydroquinone 1–7 and their mesomorphic properties are described. The title substances exhibit a large range of mesophases and clearing points about 40–50°C higher than that of the analogous esters of benzoi cacids. 4-Benzoyloxyphenyl trans-4-n-alkylcyclohexanecarboxylates 8–11 show nematic properties.  相似文献   

3.
Synthesis of pyrazolo[4′,3′ :-5,6′pyrido]1,2-a benzimidazoles was achieved by the condensation of 1-chloro-2-formyl-3-methyl pyrido[1,2-a]benzimidazole-4-carbonitrile and 1-chloro-3-methyl pyrido[1,2-a]benzimidazole-2,4-dicarbonitrile with hydrazine hydrate and phenyl hydrazine. The fluorescence properties of the resulting compounds were studied. Some of the compounds when applied on polyester fibres as fluorescent brighteners gave excellent results.  相似文献   

4.
Liquid Crystals with Aliphatic Groups between Cyclohexane Rings – Synthesis of 1,4-Bis(4-n-alkylcyclohexyl)butanes and Esters of 4-[4-(4-n-Alkylcyclohexyl)-butyl]cyclohexanols The synthesis of 1,4-bis-(4-n-alkylcyclohexyl) butanes ( 1 ), esters of 4-[-(4-n-alkylcyclohexyl)butyl]cyclohexanols ( 2 ) and some analogous aromatic compounds are described. The thermal stability of mesophases of these compounds are in the order of the analogous ethylene-bridged liquid crystals. The reason for this result seems to be the combination of molecular rigidity and conformational flexibility.  相似文献   

5.
Synthesis of Heterocyclically Substituted-4-Piperidinyl-1,4-dihydropyridines by Ring Closure Reactions at a N-Acylthioamide- or at a N-Acylisothioamide-Side-Group A series of 4-(2′-methylenepiperidin-4′-yl)-1,4-dihydropyridines [ 5–7 and 9–11 ] with a heterocyclic substituent at the methylene group is prepared by reaction of the nonsubstituted compound 1 with benzoylisothiocyanate or ethoxycarbonylisothiocyanate to the N-benzoylthioamide 2 or the N-ethoxycarbonylthioamide 3 , transformation of 2 into the isothioamide 4 by S-methylation, and subsequent ring closure of 2, 3 or 4 with hydrazine, methylhydrazine, phenylhydrazine, 1,2-diaminoethane, 1,2- and 1,3-diaminopropane, o-diaminobenzene and o-aminophenol.  相似文献   

6.
Synthesis and Reaction Behaviour of N-(3-Chlorobenzo[b]thiophene-2-carbonyl)-imino-dithiocarbonic Derivatives 3-Chlorobenzo[b]thiophene-2-carbonyl-chloride 1 was treated with potassium rhodanide to afford the appropriate acyl isothiocyanate 3 , which adds nucleophilic agents as amines and thioles in good yields. Addition of methanethiole and subsequent alkylation of the dithiocarbamate 7 gives S, S-dimethylimino-dithiocarbonate 8 . 3-Chlorobenzo[b]thiophene-2-carboxamide 2 reacts with carbon disulphide and phenyl isothiocyanate by chlorine substitution and cyclisation to benzo[b]thieno[2, 3-e]thiazines 9, 10 or 11 . The structure of the final products were determined by analytical and spectroscopical dates.  相似文献   

7.
New Synthesis of Substituted 4-Amino-quinazolines and Their Heteroanaloga N-Chloracetyl-anthranilonitriles react with potassium thiocyanate in the presence of alcohol to the (4-aminoquinazolin-2-yl-thio)-acetic acid ester ( 5 ). In the presence of water or primary amine the acetic acid derivative ( 6 ) or the acetic acid amide derivatives ( 7 ) are obtained. 2,4-Diaminoquinazolines ( 8 ) arise if vigorous reaction conditions are employed. With 2-chloracetylamino-cyclopent-1-en-carbonitrile as starting material the pyrimidines ( 11 ) are formed from the reaction with potassium thiocyanate. Analogously, (4-pyrimidyl-2-yl-seleno)-acetic acid ester ( 12 ) and (thiazolo[4,5-d]pyrimid-2-yl-seleno)-acetic acid derivatives ( 16 ) can be prepared with potassium selenocyanate. N-Chloracetyl derivatives of 5-membered heterocycles with enamino-nitrile structure ( 13 , 15 , 18 , 20 ) react with potassium thiocyanate to yield thieno[2,3-d]-, thiazolo[4,5-d]-, pyrrolo[2,3-d]-, furo[2,3-d]- and pyrazolo[4,3-d]pyrimidines ( 14 , 16 , 19a , 19b , 21 ).  相似文献   

8.
介绍了以2,2’-双(4-羟基苯基)丙烷、对氯硝基苯,碱金属碳酸盐或碱金属氢氧化物为原料,在合适的溶剂中合成2,2’-双[4-(4-硝基苯氧基)苯基]丙烷,再经不同还原方法制备2,2’-双[4-(4-氨基苯氧基)苯基]丙烷。并从反应工艺条件、产品收率、产物纯度、是否适合规模化生产等方面阐述了制备2,2’-双[4-(4-氨基苯氧基)苯基]丙烷方法的优缺点。通过比较、分析指出了2,2’-双[4-(4-氨基苯氧基)苯基]丙烷的研究和发展方向。  相似文献   

9.
Synthesis and Retention Behaviour of Smectic 2,5-Diphenyl-pyrimidines The synthesis of 2-[4-n-alkylphenyl]-5-[4-n-alkoxy-phenyl]-pyrimidines 3 , as well as the gas chromatographic investigations concerning the retention behaviour of their smectic A, C, F and G modifications for the substituted benzenes are described. Starting from the calculated enthalpies of solution and activity coefficients the intermolecular interactions in the range of terminal groups are discussed. The polarity of the stationary phases is proved by their chemical structure and only by a small part corresponding structure of the mesophases.  相似文献   

10.
Tetrathiafulvalenes. XIX. Synthesis and Properties of Electron Conducting Poly-Dithiolene Complexes with Ethylene Tetrathiolat and Tetrathiafulvalene Tetrathiolat as Bridge Ligands [1,3]-Dithiolo[4,5-d]-1,3-dithiol-2,5-dione 7 and 5-(5-oxo[1,3]-dithiolo[4,5–d]1,3-dithiole-2-ylidene)[1,3]-dithiolo[4,5–d]1,3–dithiol-2-one 8 were synthesised from 1,3-dithiole-2-thione-4,5-dithiolat. The ligands react with salts of iron, cobalt, nickel, palladium, platinum and copper to give the polymer complexes 22a–g and 23a–e , respectively. Irradiation of 7 in the presence of iron penta-, dicobalt octa- or nickel tetracarbonyl gives the corresponding dithiolene complexes 21a–c . The amorphous insoluble polymer complexes from types 21, 22 , and 23 have been characterised by i.r.-spectroscopy, susceptibility and conductivity measurements. The nickel complexes have the highest electrical conductivity (σRT ∼ 10−1Ω−1cm−1, pellets) with a very low activation energy (0,045 eV, 100–300 K) A high electron delocalization in the direction of the polymer chain and an easy charge transfer from chain to chain is supposed.  相似文献   

11.
The Synthesis of Pyrimidine-2,4-diones from Ketones and Urea By reaction of urea with 2-alkylcyclohexanones or with 2-alkylcyclohexanonecarboxamides 8-alkyl-5,6,7,8-tetrahydrobenzo-[1,2-d]pyrimidine(1H,3H)-2,4-diones ( 5a–i ) are formed. Cyclohexanone or cyclohexanone-2-carboxamide with urea form 5,6,7,8-tetrahydro-benzo-[1,2-d]pyrimidine(1H,3H)-2,4-dione ( 3 ). Menthone, 2,6-dimethylcyclohexanone, 3,5-diphenylcyclohexanone, cyclooctanone and cyclododecanone with urea yield pyrimidinediones 9, 10, 11, 12a and 12b .  相似文献   

12.
Synthesis and physicochemical properties of the new glycidyl methacrylate, styrene, and bis[4(2‐hydroxy‐3‐methacryloyloxypropoxy)phenyl]sulfide terpolymers of different crosslinking degrees are presented. The terpolymers were obtained in the form of regular microspheres by suspension polymerization. The epoxy group content, thermal properties (DSC, thermogravimetric analysis), and swelling characteristic of the functional microspheres were examined. In addition, a selected terpolymer was modified in the epoxide ring opening reaction with diethylenetriamine. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

13.
A novel fluorinated diamine monomer, 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]propane (2), was prepared through the nucleophilic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride with 2,2‐bis(4‐hydroxyphenyl)propane in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides were synthesized from diamine 2 and various aromatic dianhydrides 3a–f via thermal imidization. These polymers had inherent viscosities ranging from 0.73 to 1.29 dL/g. Polyimides 5a–f were soluble in amide polar solvents and even in less polar solvents. These films had tensile strengths of 87–100 MPa, elongations to break of 8–29%, and initial moduli of 1.7–2.2 GPa. The glass transition temperatures (Tg) of 5a–f were in the range of 222–271°C, and the 10% weight loss temperatures (T10) of them were all above 493°C. Compared with polyimides 6 series based on 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane (BAPP) and polyimides 7 based on 2,2‐Bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane (6FBAPP), the 5 series showed better solubility and lower color intensity, dielectric constant, and lower moisture absorption. Their films had cutoff wavelengths between 363 and 404 nm, b* values ranging from 8 to 62, dielectric constants of 2.68–3.16 (1 MHz), and moisture absorptions in the range of 0.04–0.35 wt %. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 922–935, 2005  相似文献   

14.
A new kind of pyridine‐containing aromatic diamine monomer, 4‐phenyl‐2,6‐bis[4‐(4‐aminophenoxy)phenyl]‐pyridine (PAPP), was successfully synthesized by a modified chichibabin reaction of benzaldehyde and a substituted acetophenone, 4‐(4‐nitrophenoxy)‐acetophenone (NPAP), followed by a reduction of the resulting dinitro compound 4‐phenyl‐2,6‐bis[4‐(4‐nitrophenoxy)phenyl]‐pyridine (PNPP) with Pd/C and hydrazine monohydrate. The aromatic diamine was employed to synthesize a series of new pyridine‐containing polyimides by polycondensation with various aromatic dianhydrides in N‐methy‐2‐pyrrolidone (NMP) via the conventional two‐step method, i.e., ring‐opening polycondensation forming the poly (amic acid)s and further thermal or chemical imidization forming polyimides. The inherent viscosities of the resulting polyimides were in the range of 0.79–1.13 dL/g, and most of them were soluble in common organic solvents such as N,N‐dimethylacetamide (DMAc), NMP, and tetrahydrofuran (THF), etc. Meanwhile, strong and flexible polyimide films were obtained, which had good thermal stability, with the glass transition temperatures (Tg) of 268–338°C and the temperature at 5% weight loss of 521–548°C in air atmosphere, as well as outstanding mechanical properties with tensile strengths of 89.2–112.1 MPa and elongations at break of 9.5–15.4%. The polyimides also were found to possess low dielectric constants ranging from 2.53 to 3.11. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 212–219, 2007  相似文献   

15.
Derivatives of Halogenated Aldehydes. IX. The Synthesis of Dialkyl-1,2,2,2-tetrachloroethyl- and Alkyl-phenyl-1,2,2,2-tetrachloroethyl Phosphates Dialkyl-1,2,2,2-tetrachloroethyl- ( 3a – t ) and alkyl-phenyl-1,2,2,2-tetrachloroethyl phosphates 3u , v are prepared by reactions of 1,2,2,2-tetrachloroethyl phosphorodichloridate 1 with one mole of an alcohol or phenol to give alkyl(phenyl)-1,2,2,2-tetrachlorethyl phosphorochloridates 2a – k , followed by treatment of the latter with a second alcohol. The n.m.r. spectra of 2 and 3 are discussed.  相似文献   

16.
2-氟-4-(反式-4-烷基环己基)苯基硼酸的合成   总被引:2,自引:0,他引:2  
李娟利  安忠维 《精细化工》2006,23(3):310-312
以1-(反式-4-烷基环己基)-3-氟苯与丁基锂、硼酸三丁酯、叔丁醇钾为反应物合成了2-氟-4-(反式-4-烷基环己基)苯基硼酸化合物3个,总收率为52%~56%,分别用IR,1HNMR对其结构进行了鉴定。优化了反应条件:n[1-(反式-4-烷基环己基)-3-氟苯]∶n(叔丁醇钾)∶n(丁基锂)∶n(硼酸三丁酯)=1∶2∶1.2∶1.5,反应温度-85~-90℃,反应时间2.5 h。叔丁醇钾的加入使反应时间由7 h缩短至2.5 h。  相似文献   

17.
Four novel bis‐benzocyclobutene‐endcapped arylene ether monomers, 1,1′‐bis[4‐(4′‐benzocyclobutenyloxy)phenyl]‐1‐phenyl‐2,2,2‐trifluoroethane (BOPP3FE), 1,1′‐bis[4‐(4′‐benzocyclobutenyloxy)phenyl]‐1‐(3′,5′‐ditrifluoromethyl)phenyl‐2,2,2‐trifluoroethane(BOPP9FE), 2,2′‐bis[4‐(4′‐benzocyclobutenyloxy)phenyl]‐1,1,1,3,3,3‐hexfluoropropane (BOP6FP), and 2,2′‐bis[4‐(4′‐benzocyclobutenyloxy)phenyl]‐propane (BOPP) were prepared and characterized. All the four monomers showed similar curing behaviors under N2 (Differential scanning calorimetry: extrapolated onset and peak temperatures at 225–229°C and 261–263°C) and demonstrated low and steady melt viscosities between 110 and 200°C, indicating their good processability. After cure, the resulting BCB resins exhibited high Tg (232–282°C) and excellent thermal stability (T5% > 433°C). The resins also showed good mechanical properties with the flexural strengths of 68–88 MPa and the flexural modulus of 2.52–3.15 GPa. Moreover, the resins also exhibited low dielectric constants (2.58–2.88), low dissipation factors (2.7 to 8.4 × 10?4) and low water absorptions in boiling water for 24 h (0.29–0.59%). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

18.
Peptides. XXV. Synthesis of Bradykinin Analogues and Partial Sequences with Tyrosine for Electron Spin Resonance and Fluorescence Studies The syntheses of [5-tyrosine, 6-glycine]-, [8-tyrosine, 6-glycine]-, [5,8-Di-tyrosine, 6-glycine]-bradykinin, and the C-terminal partial sequences are described. The analogues have been labelled with the dansyl group or an aminoxyl radical, respectively.  相似文献   

19.
Synthesis and Reactions of 2-Arylamino-3-nitroquinolines Condensation of 1-nitro-2,2-bis(methylthio)ethylene with esters of anthranilic acid yields 2-arylamino-3-nitro-4-quinolones. 2 . Analogously, from 1-nitro-2-anilino-2-methylthioethylene and o-aminoketones, 2-anilino-3-nitroquinolines 4 are obtained which can be reduced to 2-anilino-3-amino-quinolines 7 . The latter undergo cyclizations by usual methods to yield substituted triazolo-, imidazolo-, diazepino- and pyrazino-quinolines 9–12 . Reaction of ethyl-2-aminothiophene-3-carboxylates with 1-nitro-2-anilino-2-methylthio-ethylene affords 2-anilino-3-nitrothieno[2,3-b]-4-pyridones 5 .  相似文献   

20.
报道了手性添加剂(S)-(-)-4-[反式-4’-(反式-4"-丙基环己基)-环己基]-1-(1-甲基庚氧基)-2,6-二氟苯的合成方法,通过格氏偶联、硫酸氢钾催化脱水、催化氢化、顺反异构化、超低温反应、双氧水氧化、M itsunobu成醚反应共7步反应合成了目标产物,总收率21%。经IR、MS、1H NMR鉴定,结构正确,并测定了其扭曲力。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号