- Intermediates Formed in the Reactions of Organocuprates with α,β-Unsaturated Nitriles
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Conjugate additions of organocuprates are of outstanding importance for organic synthesis. To improve our mechanistic understanding of these reactions, we have used electrospray ionization mass spectrometry for the identification of the ionic intermediates formed upon the treatment of LiCuR2?LiCN (R=Me, Bu, Ph) with a series of α,β-unsaturated nitriles. Acrylonitrile, the weakest Michael acceptor included, did not afford any detectable intermediates. Fumaronitrile (FN) yielded adducts of the type Lin?1CunR2n(FN)n?, n=1–3. When subjected to fragmentation in the gas phase, these adducts were not converted into the conjugate addition products, but re-dissociated into the reactants. In contrast, the reaction with 1,1-dicyanoethylene furnished the products of the conjugate addition without any observable intermediates. Tri- and tetracyanoethylene proved to be quite reactive as well. The presence of several cyano groups in these substrates opened up reaction pathways different from simple conjugate additions, however, and led to dimerization and substitution reactions. Moreover, the gas-phase fragmentation behavior of the species formed from these substrates indicated the occurrence of single-electron transfer processes. Additional quantum-chemical calculations provided insight into the structures and stabilities of the observed intermediates and their consecutive reactions.
- Putau, Aliaksei,Brand, Harald,Koszinowski, Konrad
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- Synthesis of isoornithines and methylputrescines. An evaluation of their inhibitory effects on ornithine decarboxylase
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2-(Aminomethyl)-4-aminobutyric acid (isoornithine), 3-methylisoornithine, and 2,3-dimethyl-isoornithine were not decarboxylated by liver ornithine decarboxylase (ODC, EC 4.1.1.17) of thioacetamide-treated rats but were good competitive inhibitors of the enzyme (K(i) ranged from 0.72 to 1.79 mM). When assayed in vivo in the treated rats, the above mentioned isoornithines were also found to inhibit liver ODC when administered 1 h before sacrifice. When the methylputrescines formally derived from the decarboxylation of several isoornithines were assayed on rat liver ODC, it was found that only 2,3- dimethylputrescine decreased the enzymatic activity. When assayed in vivo, it was found to decrease ODC activity by 60%, when the latter was measured 1 h after administration. The effect was reverted 4 h after administration of the drug. Isoornithines were not taken up by H-35 hepatoma cells; hence they did not affect their ODC activity. 2,3-Dimethylputrescine however, was transported into the cells and significantly decreased its ODC activity.
- Aizencang,Frydman,Giorgieri,Sambrotta,Guerra,Frydman
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- Preparation method of ethyl 2,3-dicyanopropionate
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The invention discloses a preparation method of ethyl 2,3-dicyanopropionate. The preparation method comprises the steps of adding a liquid sodium cyanide aqueous solution into a reaction tank, conducting concentrating and dehydrating, and then adding dichloromethane to separate water; conducting cooling after the reaction is qualified, adding ethyl cyanoacetate, paraformaldehyde and a catalyst, keeping the temperature for reaction until the reaction is finished, starting to add hydrochloric acid for acidification, and conducting standing for layering to obtain a dichloromethane organic layer;and washing the organic layer with water, removing dichloromethane to obtain a crude product, and performing vacuum distillation to obtain a finished product. According to the method, dichloromethaneis directly used as a reaction solvent, and a small amount of catalyst is added, so that the reaction period is short, the solvent is easy to recover, and the used liquid sodium cyanide is safer to store and use compared with solid sodium cyanide.
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Paragraph 0019-0026
(2021/02/20)
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- Synthesis process of ethyl 2, 3-dicyanopropionate
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The invention discloses a synthesis process of ethyl 2, 3-dicyanopropionate. The method comprises the following steps: adding dimethylformamide and sodium cyanide into a dissolving kettle, stirring ata high speed, synthesizing with dimethylformamide and paraformaldehyde, dropwise adding ethyl cyanoacetate, stirring, standing for layering, continuously distilling the layered water layer, and enabling an organic layer to enter a rectifying kettle, thereby obtaining the ethyl 2, 3-dicyanopropionate product. The process is reasonable, the generated hazardous wastes are small, the yield is high, the raw materials are recovered by distilling the wastewater under reduced pressure and then rectifying the wastewater through the rectifying kettle, so that the production cost is saved, the residualwastewater is further treated, the discharge of the wastewater is reduced, and the environment is protected.
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Paragraph 0009-0017
(2020/08/30)
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- Production process of ethyl 2,3-dicyanopropionate
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The invention provides a production process of ethyl 2,3-dicyanopropionate. The production process comprises the following steps: S1, premixing of raw materials: adding ethyl cyanoacetate, dimethyl sulfoxide and diethyl malonate into a reaction kettle, and carrying out mixing and stirring to form a premixture; S2, a synthetic reaction: adding sodium cyanide and paraformaldehyde into the reaction kettle, and carrying out a constant-temperature reaction for 15-20 h under stirring and mixing conditions to form a reaction mixed solution; S3, addition of acid; step S4, extraction; S5, reduced-pressure distillation and recovery; and S6, rectification: removing a small amount of front fraction impurities to obtain a red oily target product, namely ethyl 2,3-dicyanopropionate. The raw materials ofthe process are composed of, in parts by weight, 100 parts of ethyl cyanoacetate, 100-150 parts of dimethyl sulfoxide, 60-100 parts of sodium cyanide, 50-80 parts of paraformaldehyde, and 20-30 partsof diethyl malonate. The production process of ethyl 2,3-dicyanopropionate in the invention provides has the advantages of high safety, high product yield and few byproducts.
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Paragraph 0028-0083
(2020/09/30)
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- Preparing method of 2,3-dicyanopropionate
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The invention discloses a preparing method of 2,3-dicyanopropionate, which comprises: taking diethyl malonate and glycolonitrile as raw materials, reacting in a methanol solvent of sodium methoxide to obtain an intermediate I alpha-cyanmethyl-diethyl malonate, reacting the intermediate with ammonia gas in a methylbenzene solvent to obtain an intermediate II 2-acylamino-3-cyan ethyl propionate reaction solvent, and finally reacting the intermediate II reaction solvent with phosgene in presence of a catalyst 1,4-diazabicyclo[2.2.2]octane (DABCO for short) to obtain the product 2,3-dicyanopropionate. A highly toxic product of metal cyanide is not used as a raw material, alpha replaced (replacing hydrogen or olefinic bond, hydroxymethyl) cyanoacetic acid ester is not used as an initial raw material, the produced three wastes do not contain a metal cyanide highly toxic product and are low in processing difficulty, a recycled solvent can be used indiscriminately; an operation process is simple and safe and used raw materials are cheap and easy to obtain. A reaction yield is high, the product quality is high, the production cost is low, postprocessing is easy and easiness for industrialization is realized.
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Paragraph 0030; 0032
(2016/11/14)
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- Straightforward synthesis of 1,2-dicyanoalkanes from nitroalkenes and silyl cyanide mediated by tetrabutylammonium fluoride
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A straightforward synthesis of 1,2-dicyanoalkanes by reacting nitroalkenes with trimethylsilyl cyanide in the presence of tetrabutylammonium fluoride is described. The reaction proceeds through a tandem double Michael addition under mild conditions. Employing the hypervalent silicate generated from trimethylsilyl cyanide and tetrabutylammonium fluoride is essential for achieving this transformation. Mechanistic studies suggest that a small amount of water included in the reaction media plays a key role. This protocol is applicable to various types of substrates including electron-rich and electron-deficient aromatic nitroalkenes, and aliphatic nitroalkenes. Moreover, vinyl sulfones were found to be good alternatives, particularly for electron-deficient nitroalkenes. The broad substrate scope and functional group tolerance of the reaction makes this approach a practical method for the synthesis of valuable 1,2-dicyanoalkanes.
- Kiyokawa, Kensuke,Nagata, Takaya,Hayakawa, Junpei,Minakata, Satoshi
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p. 1280 - 1285
(2015/02/19)
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- PROCESS FOR PREPARATION OF DICYANOCARBOXYLATE DERIVATIVES
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The present disclosure provides a process for preparing 2,3-dicyanopropionic acid ester of formula (I); said process comprising the following steps: i) treating an alkali metal cyanide dissolved in a solvent with a solution of 2-cyano-2-propenoic acid ester of formula (II) at a temperature ranging between 0° C. and 50° C. for a time period ranging between 2 hours and 15 hours followed by cooling below 20° C. to obtain a sodium salt of 2,3-dicyanopropionic acid ester of formula (I); and ii) neutralizing the sodium salt of 2,3-dicyanopropionic acid ester using a neutralizing agent to obtain a 2,3-dicyanopropionic acid ester of formula (I),
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Paragraph 0089
(2014/03/24)
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- PROCESS FOR SYNTHESIS FIPRONIL
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The present disclosure relates to a process for trifluoromethylsulfinyl pyrazole compound of formula I, from a compound of formula III, wherein, R, R1 and R2 represent a group containing halogen group respectively and R3 represents a perhaloalkyl.
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Paragraph 0069
(2013/03/26)
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- A PROCESS FOR PREPARATION OF DICYANOCARBOXYLATE DERIVATIVES
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The present disclosure provides a process for preparing 2, 3-dicyanopropionic acid ester of formula (I); said process comprising the following steps: i) treating an alkali metal cyanide dissolved in a solvent with a solution of 2-cyano-2-propenoic acid ester of formula (II) at a temperature ranging between 0 °C and 50 °C for a time period ranging between 2 hours and 15 hours followed by cooling below 20 °C to obtain a sodium salt of 2, 3-dicyanopropionic acid ester of formula (I); and (II) ii) neutralizing the sodium salt of 2, 3-dicyanopropionic acid ester using a neutralizing agent to obtain a 2, 3-dicyanopropionic acid ester of formula (I), (I)
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Page/Page column 15-16
(2012/11/13)
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- PROCESS FOR PREPARATION OF CYANOALKYLPROPIONATE DERIVATIVES
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A process for preparation of the compound (I) and salts thereof is provided. The process comprises reacting an alkali cyanide and paraformaldehyde to form a slurry of glycolonitrile followed by neutralizing, mixing the neutralized slurry containing glycolonitrile with an alkali ethoxide and an cyanoacetate to obtain the alkali salt of compound (I), and neutralizing the alkali salt of compound (I) to obtain the compound (I), wherein R represents a straight or branched chain alkyl having C1-C18 carbon atoms.
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Page/Page column 14-15
(2011/08/04)
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- PROCESS FOR SYNTHESIS OF FIPRONIL
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A process for preparation of a trifluoromethylsulfinyl pyrazole compound of formula (I) from a compound of formula (III) is provided, wherein R, R1 and R2 represent a group containing halogen respectively and R3 represents a perhaloalkyl.
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Page/Page column 20-21
(2011/10/03)
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- PROCESS FOR PREPARING SYNTHETIC INTERMEDIATES USEFUL IN PREPARING PYRAZOLE COMPOUNDS
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The invention concerns a process for preparing a compound of formula (I): wherein R9 is selected from: C1-8 alkyl, C3-8 cycloalkyl, (CH2)nPh and (CH2)n heteroaryl wherein n = 0, 1 or 2, each of which groups may be optionally substituted on any carbon atom by one or more groups selected independently from: halogen, hydroxy, cyano, nitro, C1-4 alkoxy, C1-4 haloalkoxy, C1-4 alkanoyl, C1-4 haloalkanoyl, C1-4alkylsulphinyl, C1-4 haloalkylsulphinyl, C1-4 alkylsulphonyl, C1-4 haloalkylsulphonyl, C3-8cycloalkyl and C3-8 halocycloalkyl; and R9 can be hydrogen; which process comprises the reaction of a cyanoacetate of formula (II): wherein R9 is as defined above, with formaldehyde cyanohydrin and an inorganic base in a polar solvent at a temperature not exceeding 20°C.
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Page/Page column 11-12
(2008/06/13)
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- Substituted arylpyrazoles
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This invention relates to a range of 1-aryl-4-cyclopropylpyrazoles in which there is at least one fluorine attached to the cyclopropyl ring, to compositions comprising such compounds, processes to their synthesis and their use as parasiticides.
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Page/Page column 22
(2008/06/13)
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- Phenylpyrazole Insecticide Photochemistry, Metabolism, and GABAergic Action: Ethiprole Compared with Fipronil
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Ethiprole differs from fipronil, the major phenylpyrazole insecticide, only in an ethylsulfinyl substituent replacing the trifluoromethylsulfinyl moiety. This study compares their photochemistry, metabolism, action at the γ-aminobutyric acid (GABA) receptor, and insecticidal potency. On exposure to sunlight as a thin film, ethiprole undergoes oxidation (major), reduction, and desethylsulfinylation but not desulfinylation whereas the major photoreaction for fipronil is desulfinylation. Metabolic sulfone formation is more rapid with ethiprole than fipronil in human expressed CYP3A4 in vitro and mouse brain and liver in vivo. High biological activity is observed for the sulfide, sulfoxide, sulfone, and desulfinyl derivatives in both the ethiprole and the fipronil series in GABA receptor assays (human recombinant β3 homomer and house fly head membranes) with [3H]EBOB and in topical toxicity to house flies with and without the P450-inhibiting synergist piperonyl butoxide. On an overall basis, the ethiprole series is very similar in potency to the fipronil series.
- Caboni, Pierluigi,Sammelson, Robert E.,Casida, John E.
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p. 7055 - 7061
(2007/10/03)
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- Processes for preparing pesticidal intermediates
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PCT No. PCT/EP97/01036 Sec. 371 Date Dec. 1, 1998 Sec. 102(e) Date Dec. 1, 1998 PCT Filed Mar. 3, 1997 PCT Pub. No. WO97/32843 PCT Pub. Date Sep. 12, 1997A process for preparing a compound of the formula wherein R is C1-C18 alkyl by reacting a compound of the formulaRO2C-CH2CN(II)with a cyanide salt and formaldehyde or source thereof. Compounds of formula (I) are useful intermediates to pesticidally active compounds.
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- Mechanisms for selective toxicity of fipronil insecticide and its sulfone metabolite and desulfinyl photoproduct
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Fipronil, an N-phenylpyrazole with a trifluoromethylsulfinyl substituent, initiated the second generation of insecticides acting at the γ-aminobutyric acid (GABA) receptor to block the chloride channel. The first generation includes the polychlorocycloalkanes α-endosulfan and lindane. In this study, we examine the mechanisms for selective toxicity of the sulfoxide fipronil and its sulfone metabolite and desulfinyl photoproduct relative to their target site interactions in vitro and ex vivo and the importance in fipronil action of biooxidation to the sulfone. Differences in GABA receptor sensitivity, assayed by displacement of 4'-ethynyl-4-n-[2,3-3H2]- propylbicycloorthobenzoate ([3H]EBOB) from the noncompetitive blocker site, appear to be a major factor in fipronil being much more toxic to the insects (housefly and fruit fly) than to the vertebrates (humans, dogs, mice, chickens, quail, and salmon) examined; in insects, the IC50s range from 3 to 12 nM for fipronil and its sulfone and desulfinyl derivatives, while in vertebrates, the IC50 average values are 1103, 175, and 129 nM for fipronil, fipronil sulfone, and desulfinyl fipronil, respectively. The insect relative to the vertebrate specificity decreases in the following order: fipronil > lindane > desulfinyl fipronil > fipronil sulfone > α-endosulfan. Ex vivo inhibition of [3H]EBOB binding in mouse brain is similar for fipronil and its sulfone and desulfinyl derivatives at the LD50 dose, but surprisingly, at higher doses fipronil can be lethal without detectably blocking the [3H]EBOB site. The P45 inhibitor piperonyl butoxide, acting in houseflies, increases the metabolic stability and effectiveness of fipronil and the sulfone but not those of the desulfinyl compound, and in mice it completely blocks the sulfoxide to sulfone conversion without altering the poisoning. Thus, the selective toxicity of fipronil and fipronil-derived residues is due in part to the higher potency of the parent compound at the insect versus the mammalian GABA receptor but is also dependent on the relative rates of conversion to the more persistent and less selective sulfone metabolite and desulfinyl photoproduct.
- Hainzl, Dominik,Cole, Loretta M.,Casida, John E.
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p. 1529 - 1535
(2007/10/03)
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