Selective cyclisation of 2, 3, 4, 5-tetra-O-acetyl-galactaric acid bis-[Alkylthio(thiocarbonyl)]hydrazide to Saccharide 1, 3, 4-Oxadiazole,Thiadiazole, and thiadiazoline derivatives

The synthesis of galactaric acid acetate bis[alkylthio(thiocarbonyl)]hydrazide ( 1 , 2 ) is described. Selective cyclisation of both hydrazides 1 and 2 was investigated. Phosphorous oxychloride as cyclising agent led to dehydrative cyclisation and produced 1, 2, 3, 4-tetra-O-acetyl-1, 4-bis(5-S-methyl or — benzyl) 1, 3, 4-thiadiazol-2-yl galactotetritol ( 3 ) or ( 4 ). While thionyl chloride led to dehydrosulfurization and gave 1, 2, 3, 4-tetra-O-acetyl-1, 4-bis(5-S-methyl or -benzyl)-1, 3, 4-oxadiazol-2-yl galactotetritol ( 5 ) or ( 6 ). Finally with triethyl orthoformate as cyclising agent, compounds 1 or 2 , gave 3, 3′-(2, 3, 4, 5-tetra-O-acetyl-galactar-1.6 dioyl)bis[2-ethoxy-2, 3-dihydro-5-S-methyl or benzyl 1, 3, 4-thiadiazole] ( 7 ) or ( 8 ).     

Enhancing electrochromic and kinetic properties of poly(2,3-bis(4-tert-butylphenyl)-5,8-di(1H-pyrrol-2-yl) quinoxaline) by copolymerization

Electrochemical copolymerization was utilized to combine several properties into a single material in order to obtain a highly stable polymer with a low band gap to meet the requirements for color variation. In that sense, two new donor acceptor type electrochromic copolymers of 2,3-bis(4-tert-butylphenyl)-5,8-di(1H-pyrrol-2-yl) quinoxaline (TBPPQ) with bis(3,4-ethylenedioxythiophene) (BiEDOT) and with 4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-dodecyl-2H-benzo [1,2,3] triazole (BEBT) were synthesized by electrochemical polymerization. Polymers revealed multicolor electrochromic properties with distinct accessible states and low operation potentials. Electrochromic and kinetic properties of polymers were investigated using cyclic voltammetry (CV) and in situ UV-vis-NIR spectroscopy.     

Bornane with integrated push–pull butadienes

The {3-[bis(alkylthio)methylene]-1,7,7-trimethyl-bicyclo[2.2.1]hept-2-ylidene}malononitriles ((1R,4S)- 2 , (1S,4R)- 2 and (1R,4S)- 3 ) were prepared starting from 1,7,7-trimethyl-bicyclo[2.2.1]hept-2-ylidenemalononitriles (1R, 4R)- 1 and (1S,4S)- 1 ) arisen from (+)-, (–)-camphor. The reaction of (1R,4S)- 2 with bromine yielded the (1S,8R)-8,11,11-trimethyl-3-methylthio-5-oxo-4-thiatricyclo-[6.2.1.0^2,7]undeca-2,6-diene-6-carbonitrile ( 8 ) after hydrolysis of the initially formed (1S,8R)-6-cyano-8,11,11-trimethyl-3-methylthio-4-thia-tricyclo[6.2.1.0^2,7]undeca-2,6-diene-5-iminium bromide ( 7 ).     

3,3-Bis[alkylthio]-phenylacrylaldehyde als Bausteine für Thiophene und Pyrazole

3,3-Bis[alkylthio]-2-phenylacrylaldehydes as Building Sets for Thiophenes and Pyrazoles Alkylation of the dithiolate 2 either with methyliodide and α-CH-acid halogenated compounds R² CH₂ X or only with the latter reagent yields ketene S,S-acetals 3 . Base catalyzed cyclization of 3 leads to the thiophenes 4 Reaction of 3,3-bis[methylthio]-2-phenylacrylaldehyde 3f with hydrazine affords a mixture of aldehydrazone 5 and aldazine 6 . The pyrazole 7a is obtained by refluxing 5 in 1-butanol. Mass spectra of the pyrazoles 7b, c and reaction of 3f with aniline prove the attack of a nucleophile on the formyl group in the first step.     

Epoxy systems with improved water resistance,and the non-fickian behaviour of epoxy systems during water ageing

N,N-Bis (2, 3-epoxypropyl) aniline and 4,4′-methylenebis-[N,N-bis (2,3-epoxypropyl) aniline] containing bromo, chloro, trifluoromethyl or polyfluoroalkoxy substituents were synthesised and cured with aromatic diamines in order to investigate the effect of substituted halogen on water absorption. Significant improvements were achieved: thus use of 4,4′-methylenebis-[N, N-bis (2, 3-epoxypropyl)-3, 5-dichloroaniline] and 4,4′-methylenebis-[N,N-bis (2,3-epoxypropyl)-3-(trifluoromethyl) aniline] instead of 4,4′-methylenebis-[N,N-bis (2,3-epoxypropyl) aniline] reduced the water absorption by about a half. Departures from Fickian behaviour were observed during water immersion ageing at room temperature and were a general feature of the epoxy systems examined. Plots of water absorption against the Fickian parameter (√t/d) usually showed at least mild sigmoid character and were not independent of specimen thickness. Further, slow continued uptake of water occurred during long-term ageing, and evidence is provided that the associated network distortions are reversible.     

Reactions with β-ketodianilides. I. New synthesis of Pyrido[3,4-c]pyridine Derivatives

Acetonedicarboxylic acid dianiline reacted with malononitrile, ethyl cyanoacetate or benzoylacetonitrile to give (6-amino-5-cyano-1,2-dihydro-2-oxo-1-phenylpyrid-4-yl)-acetanilide ( 3 ), (3-cyano-2,6-dioxo-1-phenyl-1,2,5,6-tetrahydropyrid-4-yl)acetanilide ( 8 ) or (3-cyano-1,6-dihydro-1,2-diphenyl-6-oxopyrid-4-yl)acetanilide ( 9 ). Compounds 3 and 8 could be cyclised into 8-amino-1,6-diphenyl-1,2,4,5,6,7-hexahydro-7-iminopyrido[3,4-c]pyridine-2,5-dione ( 4 ) and 7-amino-1,2,3,5,6,8-hexahydro-1,6-diphenylpyrido[3,4-c]pyridine-2,5,8-trione ( 10 ) respectively by heating their solutions in dimethylformamide in the presence of triethylamine. Each of 3 and 4 coupled with arenediazonium chlorides to give the corresponding arylhydrazone derivatives ( 5a–d ) and ( 6a–c ), respectively. Condensation of 4 with p-nitrosodimethylaniline yielded 8-amino-4- (p-dimethylaminophenylimino)-1,6-diphenyl-1,2,4,5,6,7-hexahydro-7-iminopyrido[3,4-c]pyridine2,5-dione ( 7 ).     

新型含吡啶环氟化二胺及其共聚聚酰亚胺的合成与性能

以3-羟基苯乙酮和苯甲醛为原料,通过改进的Chichibabin反应制备了4-苯基-2,6-双（3-羟基苯基）吡啶（m-PHPP）,再将其与2-氯-5-硝基三氟甲苯反应,合成了硝基化合物4-苯基-2,6-双[3-（4-硝基-2-三氟甲基苯氧基）苯基]吡啶（m,p-6FPNPP）,最后用Pd/C和水合肼将m,p-6FPN...     

Condensation of 4-phenyl-3,5-dicarboethoxycyclopentane-1,2-dione with primary amines

Condensation of the title compound ( 1 ) with primary aromatic amines gave the dianilides ( 2 ), which cyclized to cyclopenta[1,2-c:4,3-c′]diquinolines ( 3 ). Treatment of 1 with o-phenylenediamine or 2,3-diaminopyridine afforded cyclopenta[2,1-b:3,4- b ′]bis[1,5]benzodiazepine ( 4 ) and bis[1,5]pyrido[b]diazepine derivative ( 5 ), respectively. Whereas, with o-aminophenol a mixture of 2c and cyclopenta[2,1- b :3,4- b ′]bis[1,5]benzoxazepine ( 7 ) was obtained. Pechmann reaction of 1 with m-cresol gave the bis[1]benzopyrane ( 9 ). Mannich reaction of 1 with benzylamine afforded the 3-azabicyclo[3.2.1]octane system ( 10 ).     

Synthesis and Characterization of New Copoly(arylene ether)s Containing Naphthalene or Naphthalene/1,3,4-Oxadiazole Units

Summary Series of new copoly(arylene ether)s containing naphthalene or naphthalene/1,3,4-oxadiazole units have been obtained by polycondensation in solution starting from the following systems of monomers: 1,5 or 2,6-bis(4-fluorobenzenesulfonyl) naphthalene / 2,6-bis(4-fluorobenzoyl)naphthalene, 1,5 or 2,6-bis(4-fluorobenzen sulfonyl)naphthalene / 2,2-(oxydi-4,1-phenylene)bis[5-(4-fluorophenyl)-1,3,4- oxadiazole] and 2,6 bis-(4 fluorobenzoyl)naphthalene/2,2-(oxydi-4,1-phenylene)bis [5-(4-fluorophenyl)- 1,3,4-0xadiazole]. Hydroquinone and 4,4dihydroxy benzophenone have been used as aromatic dihydroxy compounds. The copolymers, obtained in quantitative yields, possessed inherent viscosities in the range 0.28-0.58 dl g^-1, had good thermal stability (10% weight loss temperatures were above 460°C both in nitrogen and air) and high glass transition temperatures (in the range 190-210°C). They have been characterized by infrared analyses, GPC and wide-angle X-ray diffraction. The copolymer property-structure relationships were studied and the properties have been compared with those of the corresponding homopolymers.     

Comparative study on polyimides from 3,3′-and 4,4′-linked diphthalic anhydride

1,4-Bis(2,3-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, bis(2,3-dicarboxyphenoxy)sulfide dianhydride, bis(3,4-dicarboxyphenoxy)sulfide dianhydride, and 2,3,3′,4′-tetracarboxy diphenyl sulfide dianhydride were synthesized from 3-chlorophthalic anhydride and 4-chlorophthalic anhydride. Bis(2,3-dicarboxyphenyl)sulfone and bis(3,4-dicarboxyphenyl)sulfone were obtained by the oxidation of the corresponding bis(dicarboxyphenyl)sulfide by hydrogen peroxide. The polyimides from the dianhydrides mentioned above and 4,4′-oxydianiline were prepared. The properties, such as dynamic mechanical behavior, thermooxidative stability, stress-strain behavior, chemical resistance, and permeability to some gases have been in investigated for the isomeric polyimides. © 1996 John Wiley & Sons, Inc.     

Preparation and properties of new π-conjugated polyquinoxalines with aromatic fused rings in the side chain

Summary New π-conjugated polyquinoxalines with aromatic fused rings in their side chain have been prepared. Dehalogenative organometallic polycondensation of 5,8-dibromo[2,3-b]-acenaphthenequinoxaline and 5,8-dibromo[2,3-b]phenanthrenequinoxaline with a zerovalent nickel complex afforded poly([2,3-b]acenaphthenequinoxaline-5,8-diyl) (P(5,8-Qx(ace))) and poly([2,3-b]phenanthrenequinoxaline-5-8-diyl) (P(5,8-Qx(phen))) in high yields. P(5, 8-Qx(ace)) had an [η] value of 0.23 dL g⁻¹ and showed absorption and photoluminescence peaks at 445 and 565 nm, respectively. (P(5,8-Qx(phen))) gave absorption and photoluminescence peaks at 400 and 514 nm, respectively. XRD data indicated formation of ordered structures of the polymers in the solid. Preparation of related copolymer with thiophene is also reported. Received: 15 February 2000/Accepted: 2 March 2000     

Unique microstructure analysis of ethylene-propylene copolymer synthesized using catalytic system based on α-diimine nickel complexes: a comparative study by 13C NMR technique

The microstructure of rubber-like ethylene-propylene copolymer (MN4) produced by a mixed nickel-based system (MN) containing catalysts of dibromo[N,N′-bis(2,6-diisopropylphenyl)-2,3-butanediimine]nickel(II) n1 and dibromo[N,N′-(phenanthrene-9,10-diylidene)bis(2,6-diisopropylaniline)]nickel(II) n2 was determined by ¹³C NMR technique. Sequences distribution of ethylene (E), propylene (P), EP, inverted propylene and uninterrupted methylene and also methylene number-average sequence lengths for the copolymer (MN4) were estimated. The results obtained from the MN4 EP copolymer were compared with reported copolymers which had been synthesized using constrained geometry catalyst (CGC) and vanadium-based Ziegler-Natta catalyst. The results demonstrated that the MN4 EP copolymer had fewer alternating comonomer sequences than ethylene-propylene elastomers obtained by CGC and vanadium-based (V) catalysts. A large number of the inversion structures (66 %) and high mole percent of sequences containing a long branch (3.2 mol%) were also observed in unique microstructure of the copolymer (MN4).     

Reactions with 5,6-Diphenyl-2,3-dihydro-imidazo[2,1-b]thiazol-3-ones and 6,7-Diphenyl-2,3-dihydro-4H-imidazo[2,1-b]1,3-thiazin-4-one

2-Methyl-5,6-diphenyl-2,3-dihydro-imidazo[2,1-b]thiazol-3-one 5 and 6,7-diphenyl-2,3-dihydro-4H-imidazo[2,1-b]1,3-thiazin-4-one 6 are prepared from 4,5-diphenyl-2-mercapto-imidazole 1 . Compounds 5 and 6 react with amines or hydrazines to give the 2-(4,5-diphenyl-imidazol-2-ylthio)acet(or propan) amides (hydrazides) 7a – g and the 3-(4,5-diphenyl-imidazol-2 ylthio) propanamides(hydrazides) 8a – e , respectively. The hydrazides 7a, 7b and 8a are condensed with aromatic aldehydes to the hydrazones 9a – h and 10a – d . Compound 5 couples with aryldiazonium salts to give 2-arylazo-2-methyl-5,6-diphenyl-2,3-dihydro-imidazo[2,1-b]thiazol-3-ones 11a – d .     

Elektrochemische Carboxylierung von Cinnamoyl-1,1-bis(alkylthio)-ethylenen

Electrochemical Carboxylation of Cinnamoyl-1,1-bis(alkylthio)ethylenes Cinnamoyl-1,1-bis(alkylthio)ethylenes ( 1a–1h ) are reduced electrochemically in the presence of carbondioxide in aprotic media. The attack of CO₂ takes place either in 1- or 5-position of cinnamoyl-1, 1-bis(alkylthio)ethylenes ( 1a–1h ) depending on the nature of the aryl substituents. If CO₂ reacts in position 1 carbonic acids 3 are obtained, reaction of carbondioxide in 5- position leads to the acids 2 . The effects of different aryl substituents on the halfwave potentials and the preparative electrolyses have been investigated.     

Synthesis of Condensed 4H-Pyrans: The reaction of 1,1-dimethyl-3,5-diketocyclohexane with cinnamonitriles

Cyclohexano-4H-pyrans could be prepared by reaction of 1,1-dimethyl-3,5-diketo-cyclohexane 2 with cinnamonitriles 1 and converted into 2-amino-4-aryl-1,4-dihydro-7,7-dimethyl-5-oxocyclohexanopyridin-3-carbonitrile 7a, b ; 7,7-dimethyl-2,5-dioxo-4-phenyl-1,2,3,4-tetrahydro-cyclohexanopyridin-3-carbonitrile 8 , 5-aryl-1,1-dicyano-2-phenyl-8,8-dimethyl-1,2,3,4,6,7,8,9-octahydro-3-azaacridin-4,6-dione 12a, b and 2-thioxo-4-amino-5-aryl-3-benzoyl-2,3-dihydro-9,9-dimethylcyclohexano-[g]-4H-pyrano[2,3-d]pyrimidin-7-one 14a, b .     

Phenolation of (+)-Catechin with Mineral Acids. II. Identification of New Reaction Products

To investigate the reactions that occur in the flavanoid unit during the liquefaction of tannin in phenol, the phenolysis of (+)-catechin was studied using either H₂SO₄, HCl, or BF₃ 2H₂O as acid catalyst. In addition to 2-[3-(3,4-dihydroxyphenyl)-2-hydroxy-3-(4-hydroxyphenyl)propyl]-1,3,5-benzenetriol (1) and 2-[(3,4-dihydroxyphenyl)(4-hydroxyphenyl)methyl]-2,3-dihydro-4,6-benzofurandiol (3) that have been described previously, eight additional reaction products were isolated, four of which were compounds that have not been described previously. The novel compounds described here are: 2-[3-(3,4-dihydroxyphenyl)-2-hydroxy-3-(2-hydroxyphenyl)propyl]-1,3,5-benzenetriol (2), 2-[(3,4-dihydroxyphenyl)(2-hydroxyphenyl)methyl]-2,3-dihydro-4,6-benzofurandiol (4), 2-[(3,4-dihydroxyphenyl)(4-hydroxyphenyl)methyl]-2,3-dihydro-7-(4-hydroxyphenyl)methyl-4,6-benzofurandiol (5), and 2-(1,3,5-trihydroxyphenyl)methyl-3-(3,4-dihydroxyphenyl)-6-[(3,4-dihydroxyphenyl)(4-hydroxyphenyl)methyl]-2,3,5,6-tetrahydrobenzo[1,2-b:5,4-b′]-difuran-4-ol (6). The structures of these and other previously described products are consistent with opening of the pyran ring of catechin and reaction at C-2 by either the para or the ortho position of phenol. Additional products resulting from reaction between pyran ring cleavage products and catechin, and from reaction of cleavage products were found. Similar reactions would be expected to take place during the phenolysis of condensed tannins.     

New polymer syntheses. Part 7. New unsaturated polyurethanes: synthesis and characterization†

A novel series of polyurethanes was prepared via step-growth solution polymerization, by reaction of arylidene monomers, e g 2,5 bis(4-hydroxybenzylidene)cyclopentanone ( I ), 2,5-divanillylidenecyclopentanone ( II ), 2,6-bis(4-hydroxybenzylidene)cyclohexanone ( III ), 2,6-divanillylidenecyclohexanone ( IV ) or 2,7-bis(4-hydroxybenzylidene)cycloheptanone ( V ) with diisocyanates such as toluylene diisocyanate and methylene bis(4-phenylisocyanate). To characterize these polymers, the corresponding model compounds were prepared from monomers I–V and phenylisocyanate. The polymers were characterized by reduced viscosity measurements, IR spectroscopy, ¹H NMR, solubility and determination of their crystallinity. Characterization of the model compounds was accomplished by elemental analysis, IR and ¹H NMR spectroscopy. The thermal stabilities of the polymers were evaluated by thermogravimetric analysis. The morphology of one of these polymers was examined by scanning electron microscopy. © 1999 Society of Chemical Industry     

Optimization of supercritical CO2 extraction of dried Helichrysum italicum flowers by response surface methodology: GC-MS profiles of the extracts and essential oil

Supercritical (SC) CO₂ extraction of dried Immortelle flowers was performed at different process parameters. The optimal extraction conditions related to the yield were determined by response surface methodology (yield 4.09% at 20 MPa and 52°C). The extracts were analyzed by GC-MS and tremetone derivatives dominated: bitalin A, 12-acetoxytremetone, gnaphaliol, 1-[2-(2-methyl-2,3-dihydroxypropyl)-2,3-dihydro-1-benzofuran-5-yl]ethanone, isobutyl bitalin A, and 1-[2-(acetylprop-1-en-2-yl)-3-hydroxy-2,3-dihydro-1-benzofuran-5-yl]ethanone. Striking differences were found among the essential oil and SC-CO₂ extracts composition. The major oil compounds were γ-curcumene, α-pinene, β-selinene, α-selinene, and limonene. Mono- and sesquiterpene were found among minor constituents of the extracts. Neryl acetate was present in the extracts and essential oil.     

Donor copolymer with benzo[1,2‐b:4,5‐b′]dithiophene and quinoxaline derivative segments for photovoltaic applications

A donor copolymer Poly{2,6‐4,8‐bis(2‐ethylhexyl)benzo[1,2‐b:3,4‐b′]dithiophene‐5,8‐2,3‐bis(5‐octylthiophen‐2‐yl)quinoxaline} (PBDTThQx) with benzo[1,2‐b:4,5‐b′]dithiophene and quinoxaline derivatives was synthesized and characterized with NMR, ultraviolet–visible spectroscopy, thermogravimetric analyses, and cyclic voltammetry. Photovoltaic devices with the configuration indium tin oxide–poly(3,4‐ethylenedioxythiophene)–poly(styrene sulfonate)–PBDTThQx–[6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PC₆₁BM)–LiF–Al were fabricated, in which PBDTThQx performed as the electron donor and PC₆₁BM was the electron acceptor in the active layer. The device presented reasonable photovoltaic properties when the weight ratio of PBDTThQx:PC₆₁BM reached 1:3. The open‐circuit voltage, fill factor, and power conversion efficiency were gauged to be 0.75 V, 0.59, and 0.74%, respectively. The experimental data implied that PBDTThQx would be a promising donor candidate in the application of polymer solar cells. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40279.     

Synthesis,Characterization and Anti-Breast Cancer Activity of New 4-Aminoantipyrine-Based Heterocycles

4-Aminoantipyrine was utilized as key intermediate for the synthesis of pyrazolone derivatives bearing biologically active moieties. The newly synthesized compounds were characterized by IR, ¹H- and ¹³C-NMR spectral and microanalytical studies. The compounds were screened as anticancer agents against a human tumor breast cancer cell line MCF7, and the results showed that (Z)-4-((3-amino-5-imino-1-phenyl-1H-pyrazol-4(5H)-ylidene)methylamino)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 5, 3-(4-bromophenyl) -1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 13, 1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1-Hpyrazol- 4-yl)-3-(4-iodophenyl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 14, 3,3′-(4,4′-sulfonylbis(4,1-phenylene))bis(1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol- 4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile) 16, (Z)-1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-hydrazono-4-oxo-3-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 17, (Z)-1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-3-phenyl-2-(2-phenylhydrazono)-1,2,3,4-tetrahydro pyrimidine-5-carbonitrile 18, and (Z)-4-(3-amino-6-hydrazono-7-phenyl-6,7-dihydro pyrazolo[3,4-d]pyrimidin-5-yl)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 19 were the most active compounds with IC₅₀ values ranging from 30.68 to 60.72 μM compared with Doxorubicin as positive control with the IC₅₀ value 71.8 μM.