- Synthesis and anthelmintic activity of osthol analogs against Dactylogyrus intermedius in goldfish
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In an attempt to develop novel anthelmintic agents, our previously isolated osthol was used as lead structures for further optimization. In our research, a series of coumarin analogs, prepared from 7-hydroxy coumarin or 7-hydroxy-4-methyl coumarin, have been evaluated for their anthelmintic activities. In all of the compounds, 6 and 7 were first synthesized, and their structures were identified based on NMR and MS values. Among the candidates, 8-allyl-7-allyloxycoumarin showed better anthelmintic activity than other compounds against Dactylogyrus infestation with EC50 value of 1.81 mg/L. The quantitative structure-activity relationship (QSAR) of 16 osthol analogs with anthelmintic activity expressed as pEC50 and toxicity to goldfish expressed pLC50, such results can offer useful theoretical references for future experimental works.
- Liu, Guang-Lu,Hao, Bing,Liu, Shao-Peng,Wang, Gao-Xue
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Read Online
- Synthetic method of Wittig reagent
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The invention discloses a synthetic method of a Wittig reagent. The synthetic method comprises the following steps: (1) by taking alpha-halogenated-ester and triarylphosphine as raw materials, carrying out reaction in a two-phase solvent in presence of a halogenated metal salt catalyst, splitting phase after reaction is finished, recycling and reusing an organic phase, crystallizing an aqueous phase to obtain quaternary phosphonium salt, and recycling and reusing mother liquid; and (2) carrying out reaction on the quaternary phosphonium salt obtained in the step (1) in the aqueous phase in presence of an alkali reagent, and cooling and crystallizing after reaction is finished, so that the Wittig reagent product is obtained. The synthetic method disclosed by the invention has the advantagesthat the whole reaction process and conditions are mild, operation is easy, yield is high, cost is low, and amount of three wastes is less, so that the synthetic method disclosed by the invention isapplicable to industrial production.
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Paragraph 0022; 0023; 0029; 0030
(2018/03/24)
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- Synthesis and antimicrobial activity of N-aryl-4-(cyano/alkoxycarbonyl)-5-(pyridin-3-yl)-1H/3H-1,2,3-triazole derivatives
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A convenient synthesis of a new series of N-aryl-5-(pyridin-3-yl)-1H/3H-1,2,3-triazole-4-carbonitriles and alkyl N-aryl-5-(pyridin-3-yl)-1H/3H-1,2,3-triazole-4-carboxylic acid esters is reported. The newly synthesized 5-(pyridin-3-yl)-1,2,3-triazole derivatives are evaluated for their antibacterial and antifungal activity. Some of these triazole derivatives have exhibited moderate antimicrobial activity.
- Komsani, Jayaram Reddy,Avula, Sreenivas,Koppireddi, Satish,Koochana, Pranay Kumar,Usn, Murty,Yadla, Rambabu
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p. 764 - 772
(2015/05/13)
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- Thermal decomposition of triphenylphosphonium alkyl ester salts
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In thermolyses of molten triphenylphosphonium alkyl ester bromides and chlorides, alkyl = methyl, ethyl, isopropyl, at 130 and 225°C, initial attack of the halide ion on the methyl group gives the methyl halide and ylid 1, Ph3P = CH2, which can be methylated, or is protonated by the phosphonium salt with transylidation giving Ph3P+-CH3X-, X = Br, Cl. The initial reactions of the ethyl or isopropyl esters are with the halide ion, X-, as a base giving ylid, 1, which can be protonated by HX or by transylidation. The t-butyl ester generates Ph3P+-CH3X-but no products of transylidation. The first-formed ylid1, can be trapped by reactive alkyl and acyl halides, and the transient ylidic esters decompose thermally to triphenyl phosphine oxide, Ph3P = O, react further with unreacted phosphonium ester, or are trapped by added aldehyde in a Wittig reaction. The final product compositions are affected by a decrease in pressure, due to escape of volatile intermediates, and by replacement of the X- halide ion by the less nucleophilic and basic tosylate ion. Reactions under reflux, in solution in chloroform, or in suspension in benzene, are similar to those of the molten salts, but yields are generally lower at the lower temperatures. Copyright Taylor & Francis Group, LLC.
- Castaneda, Fernando,Aliaga, Christian,Acuna, Cristina,Silva, Paul,Bunton, Clifford A.
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experimental part
p. 1188 - 1208
(2009/04/16)
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- The synthesis and structural characterisation of the mercury (II) halide complexes of the phosphorus ylide carbethoxymethylenetriphenylphosphorane
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The reaction of the ylide carbethoxymethylenetriphenylphosphorane (EPPY), Ph3PCHCOOEt, with mercury (II) halides has been investigated. The resulting dimeric mercury (II)-ylide complexes are isostructural and of the form [(EPPY)(HgX2)]2 where X is either bromine (1), chlorine (2), or iodine (3). These complexes have been characterised by spectroscopic techniques and X-ray diffraction. The ylide ligands have been shown to be C-coordinated to the mercury (II) atom.
- Spencer, Elinor C.,Baby Mariyatra, Mahimaidoss,Howard, Judith A.K.,Kenwright, Alan M.,Panchanatheswaran, Krishnaswamy
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p. 1081 - 1086
(2007/10/03)
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- Synthesis and Structure of Mixed Phosphonium-iodonium Ylide
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A mixed phosphonium-iodonium ylide, phenyliodoniumethoxycarbonylmethylenetriphenyl-phosphorane borofluoride, was synthesized. Its structure was established by means of X-ray diffraction analysis. Temperature dependence of 1H, 13C, and 31P spectra of the ylide synthesized was investigated. A dynamic equilibrium between Z and E-isomers was observed.
- Matveeva,Podrugina,Grishin,Tkachev,Zhdankin,Aldoshin,Zefirov
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p. 536 - 541
(2007/10/03)
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- 1-Substituted-3-dimethylaminoprop-2-en-1-ones as building blocks in heterocyclic synthesis: new routes to 6-aroylpyridazin-3-ones, a,6-diaroylpyridazin-3-imines and 3-aroylpyrazolo[5,1-c][1,2,4]triazines
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The Wittig reaction of 2-arylhydrazono-3-oxopropanals 2c,d with ethyl triphenylphosphonioacetate in the presence of methanesulfinylmethyl carbanion affords 2-substituted 6-aroylpyridazin-3-ones 5a,b which were also obtained from the reaction of 2c,d with acetic anhydride and potassium acetate. 1-Sustituted-3-dimethylaminoprop-2-ene-1-ones 1b,d couple with 5-methylisoxazole-3-diazonium chloride to yield isoxazolylhydrazono-propanals 2g-h, while compounds 1a-b couple with 5-methylpyrazole-3-diazonium chloride to yield pyrazolylhydrazonopropanals that readily cyclize to pyrazolo[5,1-c][1,2,4]triazines. The reactivity of 2-arylhydrazono-3-oxopropanals 2a-f towards a variety of active methylene reagents is investigated.
- Agamy, Samia Michel
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p. 901 - 909
(2007/10/03)
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- A new synthesis of substituted imidazo[4,5-￡]pyridinones by reductive cyclisation of 4-nitro-l//-imidazol-5-yl di-, and tri-carbonyl compounds
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A new synthetic route to the biologically important imidazo[4,5-6]pyridine ring system is described. An efficient method for the condensation of 4-nitro-l//-imidazole-5-carbonyl chlorides with activated methylene compounds using magnesium ethoxide has been developed. The imidazolyl di-, and tri-carbonyl compounds formed in this process were found to be good substrates for reductive cyclisation to the little studied 4-hydroxyimidazo[4,5-i]pyridinones by either catalytic hydrogenation over palladium or by treatment with alkaline sodium borohydride in the presence of palladium. Highly oxygenated derivatives of 1-deazapurines are thus readily available by this method.
- Tennant, George,Wallis, Christopher J.,Weaver, George W.
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p. 629 - 640
(2007/10/03)
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- Improved synthesis for the rodenticides, diphenacoum and brodifacoum
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An improved synthesis of the 3-[3-(p-substituted phenyl)-1,2,3,4-tetrahydro-1-napththyl]-4-hydroxycoumarins, diphenacoum and brodifacoum, is described. The process is primarily based on the formation of one of the crucial bonds in the carbon backbone using organocopper methodology, and on the coupling of the 4-hydroxycoumarin moiety to the 3-biphenyl tetralin unit under strongly acidic conditions.
- Van Heerden, Pieter S.,Bezuidenhoudt, Barend C. B.,Ferreira, Daneel
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p. 1141 - 1146
(2007/10/03)
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- FACILE SYNTHESIS OF ALKYL 5-ALKOXY-3-OXOPENTANOATES
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A facile synthesis of several alkyl 5-alkoxy-3-oxopentanoates, based on the reductive elimination of triphenylphosphine from the readily available alkyl 5-alkoxy-3-oxo-2-(triphenylphosphoranylidene) pentanoates, is described.
- Sanchez, Ignacio H.,Larraza, Maria Isabel,Brena, Francisco Kuri,Cruz, Adrian,Sotelo, Octavio,Flores, Humberto J.
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p. 299 - 308
(2007/10/02)
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