- Synthesis of novel semi-squaraine derivatives and application in efficient dye-sensitized solar cells
-
A series of novel semi-squaraine sensitizers with various architectures and anchors have been synthesized and utilized in dye-sensitized solar cells. These dyes combine indole- or carboline-based electron rich units with strongly electron-withdrawing cyanoacetate moieties or other functional anchoring moieties. They were thoroughly characterized as per their structural, optical and electrochemical properties and the behavior of the as-prepared solar cells were examined in detail using linear sweep voltammetry, electrochemical impedance spectroscopy and DFT calculations. Amongst the herein reported dyes, AKSq1, incorporating a free hydroxyl group directly attached to the squarate ring, exerts the optimum performance in dye-sensitized solar cells, despite the fact that this dye presents the lowest extinction coefficient among the molecules under study. AKSq1 demonstrates power conversion efficiency of 2.63%, about 14% higher than the efficiency obtained with the corresponding reference dye, the commercially available, high-performance, metal-free dye D35, under the same cell fabrication and measuring conditions. This result is attributed to the presence of free squaryl hydroxyl moiety ensuring efficient dye chemisorption and the existence of a lipophilic dodecyl group preventing the aggregation of the squaraine sensitizer onto the semiconductor's surface either by itself, or via increased intercalation of the C12 chain with the chenodeoxycholic acid coadsorbent.
- Kabanakis, Antonios N.,Bidikoudi, Maria,Elsenety, Mohamed M.,Vougioukalakis, Georgios C.,Falaras, Polycarpos
-
-
Read Online
- Preparation of new nitrogen-bridged heterocycles. XXXIII. A new preparative method for thieno[3,2-α]indolizines
-
The treatment of 2-iminothieno[3,2-α]indolizine derivatives with potassium tert-butoxide generated exclusively potassium 1-(2- cyanovinyl)indolizine-2-thiolates through the ring opening of the initially formed thiin-2-imide ions. These 2-indolizinethiolates reacted with various alkylating agents to give the corresponding S-alkylated 1-vinylindolizine derivatives, and 2-acetonylthio- and 2-phenacylthio-1-(2- cyanovinyl)indolizines of these products smoothly underwent intramolecular Michael addition under the conditions employed here to afford the corresponding 2-acetyl- and 2-aroylthieno[3,2-α]indolizines in high yields with the elimination of a methylene compound.
- Kakehi,Ito,Ueda,Takano
-
-
Read Online
- NITROAZINES 25. SPECTRAL STUDY OF THE REACTION OF THE TRANSFORMATION OF 6-NITROAZOLOPYRIMIDINES BY CH-ACTIVE NITRILES
-
The methods of 1H and 13C NMR and UV spectroscopy were utilized to investigate the structure of products of the transformation of 6-nitroazolopyrimidines by CH-active nitriles.The mechanism of reactions is discussed.
- Rusinov, V. L.,Pilicheva, T. L.,Tumashov, A. A.,Egorova, L. G.,Chupakhin, O. N.
-
-
Read Online
- Radical trifunctionalization of hexenenitrile via remote cyano migration
-
A novel radical-mediated trifunctionalization of hexenenitriles via the strategy of remote functional group migration is disclosed. A portfolio of functionalized hexenenitriles are employed as substrates. After difunctionalization of the unactivated alken
- Chang, Chenyang,Wu, Xinxin,Zhang, Huihui,Zhu, Chen
-
supporting information
p. 1005 - 1008
(2022/02/01)
-
- PROCESS FOR PREPARING CYANOACETATES
-
This invention relates to a process for producing cyanoacetates involving contacting a salt of an alkyl, alkenyl, alkynyl or aryl formyl acetate with a hydroxyl amine acid under appropriate conditions and for a time sufficient to yield a cyanoacetate.
- -
-
Paragraph 0041; 0044-0045
(2021/06/22)
-
- PROCESS FOR PREPARING CYANOACETATES
-
This invention relates to a process for producing cyanoacetates using aspartic acid as a precursor.
- -
-
Paragraph 0049-0050
(2020/10/28)
-
- PROCESS FOR PREPARING CYANOACETATES
-
This invention relates to a process for producing cyanoacetates using a cyanoacetamide as a precursor.
- -
-
Paragraph 0027-0030
(2020/10/27)
-
- PROCESS FOR PREPARING CYANOACETATES
-
This invention relates to a process for producing cyanoacetates using asparagine as a precursor to cyanoacetamide, a staring material to form the cyanoacetates.
- -
-
Paragraph 0037-0037
(2020/10/28)
-
- Ethyl cyanoacetate synthetic technology
-
The invention belongs to the technical field of the organic synthesis, and provides an ethyl cyanoacetate synthetic technology. The technology is capable of, through slowly feeding sulfur trioxide inan esterification reaction process, enabling the sulfur trioxide to react with water generated by esterification, generating sulfuric acid, on the one hand, catalyzing a reaction to be rightwards performed as a catalyst, on the other hand, consuming water in a product so as to prevent a side reaction, thereby improving a product yield and reducing generation of the side reaction at the same time;and absorbing sulfur trioxide from a tail gas by using a second-level absorbing tower, and producing concentrated sulfuric acid by using a first-level tower, thereby realizing recovery of the catalyst, by-producing sodium sulfate by using a second-level tower, and realizing value improvement of the tail gas.
- -
-
Paragraph 0013-0018
(2019/02/17)
-
- Direct Pd(II)-Catalyzed Site-Selective C5-Arylation of 2-Pyridone Using Aryl Iodides
-
A straightforward Pd(II)-catalyzed general strategy was developed for the C5-selective arylation of the 2-pyridone core with easily available aryl iodides. The transformation was highly regioselective and accomplished with a wide scope and functional group tolerance. Silver nitrate played a crucial role in this direct site-selective arylation. The method was extended to synthesize biologically active molecules.
- Maity, Saurabh,Das, Debapratim,Sarkar, Souradip,Samanta, Rajarshi
-
supporting information
p. 5167 - 5171
(2018/09/13)
-
- Synthesis method of ethyl cyanoacetate
-
The invention belongs to the technical field of organic synthesis, and provides a synthesis method of ethyl cyanoacetate. During the process of esterification reactions, sulfur trioxide is slowly introduced and reacts with water generated by the esterification reactions to generate sulfuric acid; sulfur trioxide is taken as a catalyst to promote the reactions to move to the right direction, at thesame time, water is consumed, the side reactions are prevented, the product yield is increased, and the happening rate of side reactions is reduced.
- -
-
Paragraph 0013; 0015; 0016; 0017; 0020; 0023
(2019/01/08)
-
- Magnetically recoverable AlFe/Te nanocomposite as a new catalyst for the facile esterification reaction under neat conditions
-
In this work, a new Fe3O4/AlFe/Te nanocomposite was synthesized by a one-step sol–gel method. The Fe3O4 magnetic nanoparticles (MNPs) were prepared and then mixed with aluminum telluride (Al2Te3) in an alkali medium to produce the desired catalyst. After characterization of the Fe3O4/AlFe/Te nanocomposite by SEM, TEM, EDS, XRD, and ICP analyses, it was used in the esterification reaction. This heterogeneous catalyst showed high catalytic activity in the esterification of commercially available carboxylic acids with various alcohols to produce the desired esters at high conversions under neat conditions. The Fe3O4/AlFe/Te nanocomposites were separated from the reaction mixture via an external magnet and re-used 8 times without significant loss of catalytic activity.
- Alavi, Seyed Jamal,Sadeghian, Hamid,Seyedi, Seyed Mohammad,Eshghi, Hossein,Salimi, Alireza
-
-
- PROCESS FOR PREPARING ELECTRON DEFICIENT OLEFIN PRECURSORS
-
This invention relates to a process for producing electron deficient olefin precursors, such as 2-cyanoacetates, using an acid catalyzed esterification reaction.
- -
-
Paragraph 0045
(2018/07/22)
-
- Development of the First Two-Pore Domain Potassium Channel TWIK-Related K+ Channel 1-Selective Agonist Possessing in Vivo Antinociceptive Activity
-
The TWIK-related K+ channel, TREK-1, has recently emerged as an attractive therapeutic target for the development of a novel class of analgesic drugs, suggesting that activation of TREK-1 could result in pain inhibition. Here, we report the synthesis of a series of substituted acrylic acids (1-54) based on our previous work with caffeate esters. The analogues were evaluated for their ability to modulate TREK-1 channel by electrophysiology and for their in vivo antinociceptive activity (acetic acid-induced writhing and hot plate assays), leading to the identification of a series of novel molecules able to activate TREK-1 and displaying potent antinociceptive activity in vivo. Furyl analogue 36 is the most promising of the series.
- Vivier, Delphine,Soussia, Ismail Ben,Rodrigues, Nuno,Lolignier, Stéphane,Devilliers, Ma?ly,Chatelain, Franck C.,Prival, Laetitia,Chapuy, Eric,Bourdier, Geoffrey,Bennis, Khalil,Lesage, Florian,Eschalier, Alain,Busserolles, Jér?me,Ducki, Sylvie
-
p. 1076 - 1088
(2017/02/19)
-
- Polythiophene derivative electrochromic material and preparation method thereof
-
The invention discloses a polythiophene derivative electrochromic material and a preparation method thereof. The polythiophene derivative electrochromic material has the following molecular structure shown as the accompanying drawing, wherein n is 1 to 3; m is 5 to 18. Thiophene oligomer terthienyl, sexithiophene and nine thiophene are respectively used as raw materials; two aldehyde groups are respectively introduced to the tail ends of the three kinds of polythiophene through Vilsmeier-Haack reaction; cyanoacetic acid is firstly subjected to esterification and then takes a reaction with alkylamine to generate 2-cyano-acetylalkylamine; products obtained through the two steps of reaction is subjected to Knoevenagel condensation to obtain a target product. The prepared polythiophene derivative can form gel; a device prepared by using the gel as the electrochromic material does not need a film forming process; in addition, the problem that the device can easily generate liquid leakage due to the use of liquid electrolyte can also be solved.
- -
-
Paragraph 0008; 0028; 0029; 0043; 0058; 0072; 0086; 0100
(2017/09/01)
-
- Method for producing Cyanoacetamide
-
Provided is a process for producing cyanoacetic acid esters which achieves high-yield production of cyanoacetic acid esters and minimizes the generation of by-products. A process for producing cyanoacetic acid esters by esterifying cyanoacetic acid with an organic compound represented by the general formula ROH [wherein R is a C1-10 group selected from the group consisting of linear or branched saturated hydrocarbon groups, linear or branched unsaturated hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and -C2H4-O-R1 groups (wherein R1 is a linear or branched saturated hydrocarbon group, a linear or branched unsaturated hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, each group having 1 to 8 carbon atoms)] in an organic solvent other than the organic compound, wherein both a first solvent, the solubility of cyanoacetic acid in which is 1 [g/100g of solvent] or more at 25°C, and a second solvent which is substantially insoluble in water at 25°C are jointly used as the organic solvent.
- -
-
Paragraph 0025
(2016/12/12)
-
- Synthesis and structure-activity relationship study of substituted caffeate esters as antinociceptive agents modulating the TREK-1 channel
-
The TWIK-related K+ channel, TREK-1, has recently emerged as an attractive therapeutic target for the development of a novel class of analgesic drugs. It has been reported that TREK-1 -/- mice were more sensitive than wild-type mice to painful stimuli, suggesting that activation of TREK-1 could result in pain inhibition. Here we report the synthesis of a series of substituted caffeate esters (12a-u) based on the hit compound CDC 2 (cinnamyl 3,4-dihydroxyl-α-cyanocinnamate). These analogs were evaluated for their ability to modulate TREK-1 channel by electrophysiology and for their in vivo antinociceptive activity (acetic acid induced-writhing assay) leading to the identification a series of novel molecules able to activate TREK-1 and displaying potent analgesic activity in vivo.
- Rodrigues, Nuno,Bennis, Khalil,Vivier, Delphine,Pereira, Vanessa,Chatelain, Franck C.,Chapuy, Eric,Deokar, Hemantkumar,Busserolles, Jér?me,Lesage, Florian,Eschalier, Alain,Ducki, Sylvie
-
supporting information
p. 391 - 402
(2014/03/21)
-
- SYNTHESIS OF CYANOCARBOXYLIC ACID ALKYL ESTERS
-
Provided is a process for obtaining a compound of formula (I): N≡C-CH2-A-C(O)-OR, wherein Hal is halogen selected from F, Cl, Br or I, A denotes a bond or a divalent spacer selected from alkylene and arylene groups, and R is a C1-4 alkyl group, by reacting a compound of formula (II): Hal-CH2-A-C(O)-OR, wherein Hal is a halogen atom selected from F, Cl, Br and I, and wherein A and R are as defined above, with hydrogen cyanide in the presence of a first base, wherein the molar ratio between hydrogen cyanide and said first base is from 1:0.3 to 1:0.95 and the molar ratio between hydrogen cyanide to the compound of formula (II) is at least 1:1.
- -
-
Page/Page column 30-31
(2013/08/28)
-
- Process for the preparation cyano carboxylic acid esters
-
The present invention relates to a process for the preparation of a cyano carboxylic acid ester of the formula wherein R1 is a linear or branched C1-8 alkanediyl group; and R2 is a linear or branched alkyl group, a cycloalkyl group, or an aryl or arylalkyl group, wherein aryl is optionally substituted with one or more C1-8 alkyl groups; comprising reacting a halo carboxylic acid ester of the formula wherein R1 and R2 are as defined above; and Hal is fluorine, chlorine, bromine or iodine; in a reaction mixture comprising a homogeneous liquid phase, wherein the liquid phase consists of water and an organic solvent, with an alkali metal cyanide in the presence of hydrogen cyanide, optionally in the presence of a catalyst, to obtain the cyano carboxylic acid ester of the formula (I).
- -
-
Page/Page column 6
(2012/06/01)
-
- A practical system to synthesize the multiple-substituted 2,5-dihydrofuran by the intermolecular dipolar cycloaddition reactions involving acceptor/acceptor-substituted diazo reagents
-
A practical system for synthesizing the multiple-substituted 2,5-dihydrofuran through intermolecular dipolar cycloaddition reactions of acceptor/acceptor diazo reagents, aldehydes, and acetylenedicarboxylate was developed. The reactions proceeded effectively under ambient temperature with low reactant ratios. The control reactions revealed that there are two competitive paths: one forms 1,3-dioxolane and the other forms 2,5-dihydrofuran. These two paths could be controlled by modifying the steric hindrance of the diazo reagents.
- Zhu, Shifa,Chen, Lijuan,Wang, Chao,Liang, Renxiao,Wang, Xiujun,Ren, Yanwei,Jiang, Huanfeng
-
experimental part
p. 5507 - 5515
(2011/08/06)
-
- Combinatorial synthesis of 3,5-Dimethylene substituted 1,2,4-Triazoles
-
Combinatorial cyclizations of imidates and hydrazides with methylene linked R groups, generated from the corresponding nitriles and carboxylic acids, respectively, provided a large library of 3,5-dimethylene substituted 1,2,4- trizoles. 2011 Bentham Science Publishers Ltd.
- Woodard, Scott S.,Jerome, Kevin D.
-
experimental part
p. 132 - 137
(2012/04/18)
-
- Study on the Pd/C-catalyzed (retro-)Michael addition reaction of activated methylene compounds to electron-poor styrenes
-
Palladium on carbon (10 % Pd/C) efficiently catalyzes the (retro-)Michael addition of activated methylene compounds 2a-d, such as malononitrile (2b), to mono- and doubly activated styrenes 1a-h to give the adducts 3a-l. The scope and limitations are described. The Knoevenagel condensation reaction of benzaldehyde and 2b or ethyl cyanoacetate (2c) is also catalyzed by 10 % Pd/C. In these cases the Michael adducts can even be prepared in a three-component reaction. A mechanism, with as first step the oxidative addition of 2a-d to Pd0, is proposed. Palladium on carbon (10 % Pd catalyzes the (retro-)Michael addition of activated methylene compounds 2a-d to mono- anddoubly activated styrenes. The scope and limitations of the reaction are described. A mechanism is proposed. Copyright
- Nikishkin, Nicolai I.,Huskens, Jurriaan,Verboom, Willem
-
scheme or table
p. 6820 - 6823
(2011/02/26)
-
- Synthesis and antiviral bioactivities of 2-cyano-3-substitutedamino(phenyl) methylphosphonylacrylates (Acrylamides) containing alkoxyethyl moieties
-
An efficient reaction under microwave irradiation has been developed for the synthesis of a series of novel 2-cyano-3-substituted-amino(phenyl) methylphosphonylacrylates (acrylamides) II. The products obtained in shorter reaction time with moderate yields are fully characterized by elemental analysis, IR, 1H, 13C, and 31P NMR spectral data. The role of introducing various substituents and the effect of incorporating a-aminophosphonates with an alkoxyethyl moiety into the parent cyanoacrylate (acrylamide) structure are investigated. Among the studied compounds, both II-17 and II-24 displayed good in vivo curative, protection, and inactivation effects, which were comparable to those of the commercial reference ningnanmycin (inhibitory rates of 58.8, 60.2, 78.9% and 60.0, 58.9, 85.5%, respectively, at 500 mg/L against TMV). To the best of the authors' knowledge, this is the first report on the synthesis and antiviral activity of the title compounds II.
- Yang, Jia-Qiang,Song, Bao-An,Bhadury, Pinaki S.,Chen, Zhuo,Yang, Song,Xue-Jian, Cai,Hu, De-Yu,Xue, Wei
-
experimental part
p. 2730 - 2735
(2011/07/31)
-
- Synthesis and antiviral activities of cyanoacrylate derivatives containing an α-aminophosphonate moiety
-
Target compounds 8 were obtained by the reaction of alkyl 2-cyano-3,3-dimethylthioacrylate or cyarylamide (7a-7e) and α- aminobenzylphosphonate (5a-5e) under reflux condition using ethanol as solvent. Their structures were clearly verified by spectroscopic data (IR and 1H, 13C, and 31P NMR) and elemental analysis. These compounds were shown to be antivirally active in the bioassay. It was found that title compounds 8d and 8e had the same inactivation effect against tobacco mosaic virus (EC50 = 55.5 and 55.3 μg/mL) as the commercial product ningnanmycin (EC50 = 50.9 μg/mL). To the best of our knowledge, this is the first report on the synthesis and antiviral activity of cyanoacrylate derivatives containing an α-aminophosphonate moiety.
- Long, Ning,Cai, Xue-Jian,Song, Bao-An,Yang, Song,Chen, Zhuo,Bhadury, Pinaki S.,Hu, De-Yu,Jin, Lin-Hong,Xue, Wei
-
body text
p. 5242 - 5246
(2010/04/06)
-
- Unprecedented reaction between ethyl α-cyanocinnamate and o-phenylenediamine: Development of an efficient method for the transfer hydrogenation of electronically depleted olefins
-
A reaction between ethyl α-cyanocinnamate and o-phenylenediamine under thermal conditions yielded 2-cyano-3-phenyl-propionic acid ethyl ester, 2-phenyl benzimidazole, and ethyl cyanoacetate. The mechanistic revelations led to the development of a simple and efficient transfer-hydrogenation process from the in situ generated benzimidazolines to activated olefins under solventless and catalyst-free conditions. Georg Thieme Verlag Stuttgart.
- Kumar, Satish,Kapoor, Kamal K.
-
p. 2809 - 2814
(2008/02/13)
-
- Orally Bioavailable Caffeic Acid Related Anticancer Drugs
-
The present invention concerns compounds and their use to treat cell proliferative diseases such as cancer. Compounds of the present invention display significant potency as inhibitors of Jak2/STAT3 pathways and downstream targets and inhibit the growth and survival of cancerous cell lines.
- -
-
Page/Page column 17; 18
(2008/06/13)
-
- Iron(III) chloride-promoted direct conversion of aryl/alkyl cyanides to esters
-
Aryl/alkyl cyanides were quickly converted into the corresponding esters in the presence of iron(III) chloride in refluxing alcohols with very good yields. Copyright Taylor & Francis Group, LLC.
- Srinivasan,Rao, K. Srinivasa,Jayachitra,Ralte, Samuel L.
-
p. 2883 - 2886
(2007/10/03)
-
- VITRONECTIN RECEPTOR ANTAGONISTS
-
Compounds of formula (I) are disclosed which are vitronectin receptor antagonists and are useful in the treatment of osteoporosis wherein R is Het- or Ar; R is formula (a) or formula (b); or a pharmaceutically acceptable salt thereof.
- -
-
-
- Method for producing cyanoacetic acid esters
-
A method for producing cyanoacetic acid esters of general formula (I): wherein R represents on optionally substituted linear or branched C1-8 alkyl group or an aryl C1-4 alkyl group. According to the method, an alkoxypropionitrile of the general formula (II): wherein R is defined above, is oxidized to form the desired product in the presence of a catalyst, based on lead or on one of the transition metals, using oxygen or an oxygen-forming reagent.
- -
-
Page column 3
(2008/06/13)
-
- Catalyst for aromatic C—O, C—N, and C—C bond formation
-
The present invention is directed to a transition metal catalyst, comprising a Group 8 metal and a ligand having the structure wherein R, R′ and R″ are organic groups having 1-15 carbon atoms, n=1-5, and m=0-4. The present invention is also directed to a method of forming a compound having an aromatic or vinylic carbon-oxygen, carbon-nitrogen, or carbon-carbon bond using the above catalyst. The catalyst and the method of using the catalyst are advantageous in preparation of compounds under mild conditions of approximately room temperature and pressure.
- -
-
-
- Borontrifluoride etherate promoted one-pot conversion of nitriles to esters
-
One-pot borontrifluoride etherate promoted transformation of nitriles to esters was achieved by heating in corresponding alcohol as a reactant and solvent.
- Jayachitra,Yasmeen,Srinivasa Rao,Ralte, Samuel L.,Srinivasan,Singh
-
p. 3461 - 3466
(2007/10/03)
-
- Reactivity of Some Cyclohexanol Derivatives towards Sodium Ethoxide in Ethanol
-
Two series of 2-(p-aroyl)-1,3,5-tri (p-aryl)-4-carbethoxy-4-cyanocyclohexan-1-ols IIa-f and IIg-h were prepared and the structure of the new compounds IIf,g,i was established by elemental analysis and spectroscopic methods. These cyclohexanol derivatives IIa-f and IIg-k were allowed to react with sodium ethoxide in absolute ethanol afforded the corresponding trans-1,3-di-(p-aryl)-2-propenones Ia-f and Ig-k, respectively besides ethyl cyanoacetate as a bi-product. The reaction kinetics has been studied spectrophotometrically at three different temperatures and the observed rate constants were calculated. Cood Hammett correlations with ρ values of series IIa-f ranged between 0.76 and 1.34, whereas of series IIg-k they were between 1.01 and 1.54 which suggest a carbanionic character of the transition states. The values of thermodynamic parameters ΔH(act.) and ΔS(act.) confirmed the proposed multi-step mechanism.
- Darwish, A. I.
-
p. 695 - 711
(2007/10/03)
-
- Synthesis of [1′,2′,5′,2-13C4]-2′ -deoxy-D-adenosine by a chemoenzymatic strategy to enable labelling of any of the 215 carbon-13 and nitrogen-15 isotopomers
-
Enzymatic trans-N-glycosylation has been selected as the method of choice by which to couple [13C1]-adenine to [13C3]-2-deoxy-D-ribose. The enzymatic pentosylation of the labelled adenine base was achieved in a two-step/one-pot reaction, starting from thymidine labelled in the sugar ring, but not at the thymine base. The efficiency of this thymidine phosphorylase catalysed (TP-catalysed) and purine nucleoside phosphorylase catalysed (PNP-catalysed) transamination reaction was demonstrated by a high yield (91%) and stereochemical purity of the obtained [1′,2′,5′,2-13C4]-2′ -deoxy-D-adenosine. To verify that all carbon and nitrogen positions and combination of positions in both the adenine and the sugar could be substituted by 13C and 15N at a minimum of cost, each of the steps was optimised to convert the commercially available and isotopically highly enriched (99%) synthons (acetaldehyde, acetic acid, ammonia, benzylamine, formic acid, methylamine, potassium cyanide, potassium thiocyanate and sodium nitrite) as quantitatively as possible. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Ouwerkerk, Niels,Van Boom, Jacques,Lugtenburg, Johan,Raap, Jan
-
p. 2356 - 2362
(2007/10/03)
-
- Acylation through ketene intermediates
-
Carboxylic acids possessing a strong electron-withdrawing group in the α-position undergo facile dehydration upon reaction with carbodiimides to form the corresponding substituted ketenes that can react in situ with alcohols providing esters in a high yield. The ketene formed by the treatment of ethyl 2-methylmalonate with DCC was trapped in situ by a [4+2] cycloaddition with a second DCC molecule. The chemoselectivity of the acylation through the ketene intermediates was found to be substantially different from that of conventional acylation reagents showing a very low sensitivity toward the steric bulk of alcohols. A comparison of the sensitivity of the acylation to the steric bulk of alcohols supports the presence of a pseudopericyclic pathway for the nucleophilic addition of alcohols to ketenes derived from ethyl malonic and diethylphosphonoacetic acid.
- Shelkov, Rimma,Nahmany, Moshe,Melman, Artem
-
p. 8975 - 8982
(2007/10/03)
-
- Process for preparing cyanoacetic esters
-
Cyanoacetic esters of the general formula: in which R is C1-10-alkyl, C3-10-alkenyl or aryl-C1-4alkyl, are prepared by the reaction of alkali metal cyanoacetates with the corresponding halides R—X, in which X is chlorine, bromine or iodine, in an aqueous/organic two-phase system in the presence of a phase-transfer catalyst.
- -
-
-
- Synthesis of N-bonded enolatoruthenium(II) by oxidative addition of alkyl cyanocarboxylate to a ruthenium(0) complex
-
Reaction of a zero-valent ruthenium complex [Ru(cot)(cod)] 1 (cod = 1,5-cyclooctadiene; cot = 1,3,5-cyclooctatriene) with alkyl cyanoacetate in the presence of mono- and bi-dentate tertiary phosphines gave a series of hydrido(enolato)-ruthenium(n) complexes: mer-[RuH(NCCHCO2Et)(NCCH2CO2Et)(PPh 3)3] 2; trans-[RuH(NCCHCO2Et)(cod)-(dppe)] 3 (dppe = Ph2PCH2CH2PPh2); trans-[RuH(NCCR1CO2R2)(dppe)2] (R1 = H, R2 = Et 4a: or Pri 4b; R1 = Me, R2 = Et 4c) and trans-[RuH(NCCMeCO2Et)(PMePh2)4] 5. The molecular structure of 3 shows that the enolato ligand co-ordinates to the ruthenium centre via the cyano group in an octahedral geometry. These hydrido-(enolato)ruthenium(II) complexes catalyse Michael and Knoeevenagel reactions under neutral and mild conditions. The Royal Society of Chemistry 1999.
- Hirano, Masafumi,Takenaka, Atsushi,Mizuho, Yuji,Hiraoka, Makiko,Komiya, Sanshiro
-
p. 3209 - 3216
(2007/10/03)
-
- Simultaneous determination of five oxidative DNA lesions in human urine
-
A method, involving a HPLC prepurification followed by a GC/MS analysis, has been set up for the measurement of nucleic acid oxidation products in human urine. For this purpose, isotopically labeled internal standards have been prepared and used for isotope dilution mass spectrometric detection. Using this approach, four oxidized DNA bases, i.e., 5-hydroxyuracil, 5- (hydroxymethyl)uracil, 8-oxo-7,8-dihydroadenine, and 8-oxo-7,8- dihydroguanine, together with 8-oxo-7,8-dihydro-2'-deoxyguanosine have been simultaneously quantified in human urine samples. The levels of the oxidized nucleic acid constituents, as expressed in picomoles per milliliter, were determined to be, in decreasing order: 8-oxo-7,8-dihydroguanine (583 ± 376) > 5-(hydroxymethyl)uracil (121 ± 56) > 5-hydroxyuracil (58 ± 23) > 8-oxo- 7,8-dihydro-2'-deoxyguanosine (30 ± 15) > 8-oxo-7,8-dihydroadenine (7 ± 4). Attempts to determine the amount of 5,6-dihydroxy-5,6-dihydrothymine, 5- hydroxycytosine, and 2,6-diamino-4-hydroxy-5-formamidopyrimidine using the above HPLC-GC/MS method were unsuccessful.
- Ravanat, Jean-Luc,Guicherd, Pascale,Tuce, Zorana,Cadet, Jean
-
p. 802 - 808
(2007/10/03)
-
- Reaction of polycyanocyclopropanes with amine hydroiodides
-
Reactions of ethyl 1,2,2,3,3-pentacyanocyclopropanecarboxylate, l,3-dioxoindan-2-spirocyclopropane-2′,2′,3′,3′- tetracarbonitrile, 2,4,6-trioxoperhydropyrimidine-5-spirocyclopropane-2′,2′,3′, 3′-tetracarbonitrile, and 4,4-dimethyl-2,6-dioxocyclohexanespirocyclopropane-2′,2′,3′, 3′-tetracarbonitrile with amine hydroiodides yield, depending on the structure of the initial cyclopropane, 1-ethoxycarbonyl-1,2,3,3-tetracyanopropenides, ethyl 3-arylamino-2,3-dicyanoacrylates, N,N-dialkyl-4-(tricyanovinyl)anilines, (4-dimethylaminophenyl)(1,3-dioxoindan-2-yl)malononitrile, (l,3-dioxoindan-2-yl)(4-tolylamino)malononitrile, 5-[aryl(dicyano)methyl]perhydropyrimidine-2,4,6-triones, and 2-amino-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4Hchromene-3,4,4-tricarbonitrile.
- Siaka,Kayukova,Kayukov,Lukin,Khrustalev,Nesterov,Nasakin,Antipin
-
p. 1269 - 1276
(2007/10/03)
-
- Chemistry of 5-oxodihydroisoxazoles. Part 18. Synthesis of oxazoles by the photolysis and pyrolysis of 2-acyl-5-oxo-2,5-dihydroisoxazoles
-
N-Acylisoxazol-5-ones lose carbon dioxide under photochemical and thermal conditions affording iminocarbenes which undergo intramolecular cyclisation through the oxygen of the acyl group to give oxazoles. Under photochemical conditions those acylisoxazolones with electron withdrawing groups at C-4 usually give high yields of oxazoles, while those with electron donating groups at C-4 give only poor yields: the reverse is observed under thermal conditions.
- Prager, Rolf H.,Smith, Jason A.,Weber, Ben,Williams, Craig M.
-
p. 2665 - 2672
(2007/10/03)
-
- Halogenation and deuterium exchange in ethyl cyanoacetate. Enolisation mechanism and enol reactivity
-
Reactions of ethyl cyanoacetate (ECA) in 30% dioxane-water with bromine, iodine and chlorine (with [ECA]0 ? [Halogen]0) are all first-order processes and are not acid catalysed over the range studied (0.02-1.10 mol dm-3). Values of the observed first-order rate constant divided by [ECA] are very similar for the three halogens, suggesting that all three react with the enol form of ECA at or near to the diffusion limit. This enables the determination of a pKE value of 9.6 and a pKaE value for the acid dissociation of the enol of 2.1. The rate constant for enolisation is obtained by NMR measurements of the H-D exchange reaction and is shown to be independent of the acidity in the range 0.08-0.39 mol dm-3 D+. The results are consistent with the enolisation mechanism involving rate-limiting water-catalysed proton removal from the methylene group, followed by rapid protonation of the enolate. The results are discussed in terms of the enolisation of other carboxylic esters and acids.
- Eberlin, Alex R.,Williams, D. Lyn H.
-
p. 1043 - 1046
(2007/10/03)
-
- Intrinsic Reactivities of Some Carbanions in ?-Adduct Forming Reactions
-
Kinetic and equilibrium data are reported for nucleophilic attack in methanol at unsubstituted ringpositions of 1,3,5-trinitrobenzene, 2,4,6-trinitrotoluene and 1-chloro-2,4,6-trinitrobenzene by carbanions derived from dimethyl malonate, ethyl cyanoacetate and 4-nitro-, 4-cyano- and 2-cyanobenzyl cyanides.The results are used to determine intrinsic reactivities for the carbanions in these ?-adduct forming reactions and are discussed in terms of the electronic and solvent reorganisation occurring during reaction.
- Crampton, Michael R.,Stevens, Andrew J.
-
p. 1715 - 1720
(2007/10/02)
-
- CRYPTATE ACIDITY SCALES. V. EQUILIBRIUM ACIDITY OF INDICATOR CH-ACIDS IN TETRAHYDROFURAN
-
A scale of equilibrium cryptate acidity in tetrahydrofuran is constructed.Its distinguishing feature is the constancy of the contribution from ionic association.A method is proposed for determination of the constants for the association of the ions into ion pairs in dimethyl sulfoxide.
- Antipin, I. S.,Gareev, R. F.,Vedernikov, A. N.,Konovalov, A. I.
-
p. 1039 - 1044
(2007/10/02)
-
- TRIBUTYLSTIBINE MEDIATED SYNTHESIS OF 1,1,2-TRI-SUBSTITUTED CYCLOPROPANES
-
A novel method for the synthesis of 1,1,2-tri-substituted cyclopropanes is reported which involves the reaction of electron-deficient olefins with dibromomalonic ester, dibromocyanoacetic or dibromobenzeneacetic ester promoted by tri-n-butylstibine.The reaction was carried out under mild conditions to give the cyclopropane derivatives in moderate to good yields.Other R3M (M= As,Sb,Bi) reagents as promoter for this reaction have been studied and seem to be less effective than tributylstibine.
- Chen, Chen,Liao, Yi,Huang, Yao-Zeng
-
p. 3011 - 3020
(2007/10/02)
-
- Synthesis of Nitrogen-Containing Heterocycles. 3) Formation and Structure of New 1,2,4-Triazole Derivatives
-
Treatment of N(3)-amino-N(4),N(4)-dimethylaminomethylenehydrazones of aromatic carbonyl compounds with hot acetic acid resulted in the formation of symmetrical gem-bis-(3-dimethylamino-1,2,4-triazol-1-yl)methanes, (3-dimethylamino-1,2,4-triazol-1-yl)arylmethyl acetates, and (3-dimethylamino-1,2,4-triazol-1-yl)alkenes of a gem-diaryl type depending upon whether the carbonyl compound was aldehyde or ketone.
- Miyamoto, Yoshiko,Yamazaki, Chiji
-
p. 327 - 332
(2007/10/02)
-
- α-methine substituted thiophene monoazo dye
-
A compound of the formula: STR1 wherein K is a radical of a coupling component, R is a radical of a methylene-active compound, X is hydrogen or unsubstituted or substituted alkyl, aryl, or hetaryl and Y is cyano, nitro, alkanoyl, aroyl, alkylsulfonyl, arylsulfonyl, carboxyl, a carboxylic ester group or unsubstituted or substituted carbamyl. The present compound is useful for the dyeing of polyesters, nylons, cellulose esters and blends of polyesters and cellulose fibers.
- -
-
-
- Organic Azides. 5. A Simple Synthesis of Alkyl 3-Azido-2-alkenoates
-
The title compounds are derived from alkyl 2-alkynoates and aqueous sodium azide solution under ultrasonic irradiation.At low reaction temperatures the Z-configuration is favoured.Ultrasonic irradiation is decisive for good conversion and in most cases no additional stirring is necessary.Stirring without ultrasonic irradiation gives low conversion.The reaction conditions show high selectivity between nucleophilic addition and nucleophilic substitution.
- Priebe, Hanno
-
p. 640 - 645
(2007/10/02)
-
- Cyclization of Isothiosemicarbazones. Part 7. Synthesis of N-Alkenyl-1,2,4-triazoles with Anti-Saytzeff Orientation
-
Aliphatic ketone 4--3-methylisothiosemicarbazones (4) give N-alkenyl-1,2,4-triazoles (6) in moderate yields with elimination of ethyl cyanoacetate in hot acetic acid.When the carbonyl component is an unsymmetrical ketone, the reaction proceeds predominantly to afford the less substituted terminal alkenes, and little or no formation of the more substituted internal alkenes was observed, even though the internal alkene would be thermodynamically more favourable.Without an intervening isolation of the N(4)-(substituted vinyl) isothiosemicarbazones, these alkenes are obtained in much higher yields through a direct 'cycloalkenylation' of N(4)-unsubstituted isothiosemicarbazones (1) with ethyl β-ethoxy-α-nitroacrylate (3) along with a minor amount of 2(3)-(3-alkylthio-1,2,4-triazol-1-yl)alkan-2(3)-yl acetates (7).The proposed mechanism involves preferential abstraction of a proton at the less crowded alpha-carbon of the potentially formed iminium ion.
- Yamazaki, Chiji,Sakai, Mitsuru,Miyamoto, Yoshiko,Suzuki, Narumi
-
p. 1567 - 1572
(2007/10/02)
-