- The synthesis and reactions of dialkyl fluoroalkyl phosphates
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Dimethyl and diethyl fluoroalkyl phosphates were prepared from (1) a dialkyl phosphite with a fluoroalcohol, triethylamine and carbon tetrachloride, (2) a dialkyl chlorophosphate with a fluoroalcohol and triethylamine, and (3) a dialkyl chlorophosphate with the sodium salt of a fluoroalcohol. Dimethyl and diethyl (2,2,2-trifluoroethyl) phosphates reacted with bromotrimethylsilane (TMSBr) in chloroform to give two products with loss of alkyl bromide. The major product was an alkyl (trifluoroethyl) trimethylsilyl phosphate, RO(TMSO)P(O)OCH2CF3 and the minor product was a bis(trimethylsilyl) trifluoroethyl phosphate, (TMSO)2P(O)OCH2CF3. The mechanism presumably involves initial attack of an alkoxy oxygen atom on the silicon atom of bromotrimethylsilane. Diethyl (2,2,2-trifluoroethyl) phosphate is resistant to chlorination. It did not react with oxalyl or thionyl chloride in chloroform under prolonged reflux. Unlike triethyl phosphate, it did not react with phosphorus oxychloride in chloroform under reflux.
- Timperley, Christopher M.,Morton, Ian J.,Waters, Matthew J.,Yarwood, Jason L.
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Read Online
- Extraction of hexachloroplatinate from hydrochloric acid solutions with phosphorylated hexane-1,6-diyl polymers
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A series of diols (diethylene glycol, triethylene glycol, butane-1,4-diol and hexane-1,6-diol) were immobilized onto Merrifield resin and subsequently phosphorylated with dialkyl chlorophosphate (alkyl = Me, Et, Bu). The resins bearing hexane-1,6-diyl groups exhibited very good extraction abilities in regard to precious metal chloro complexes like platinum(IV), palladium(II) and rhodium(III). In batch experiments, more than 98% of Pt(IV) is extracted even when the metal and the hydrochloric acid concentration is enhanced significantly. Elution can be achieved with a solution of 0.5 mol L-1 thiourea in 0.1 mol L-1 hydrochloric acid. In the presence of other noble metals, platinum(IV) is preferentially bound. The extraction yield decreases in slightly acidic solution in the following order: Pt(IV) ≈ Pd(II) > Rh(III) and changes with increasing hydrochloric acid concentration to Pt(IV) > Pd(II) ? Rh(III). At different ratios of metal and acid, the temperature has nearly no influence on the platinum extraction. On slightly acidic media, the extraction of rhodium decreases by 30% when the temperature is increased from 10°C to 40°C. When the acid and metal concentration is enhanced, the palladium extraction decreases by 7-9%, depending on the resin.
- Hahn, Simone,Holdt, Hans-Jürgen
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Read Online
- Organophosphorus derivatives containing piperazine dithiosemicarbazones as chemotherapeutants against fungal pathogens of sugarcane
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Five novel organophosphorus derivatives have been synthesized by the reactions of O,O-diethylchlorophosphate with piperazine dithiosemicarbazones. The derivatives have been characterized on the basis of analyses and spectral (IR, 1H NMR) data. Fungicidal activities of these derivatives against Colletotrichum falcatum, Fusarium oxysporum, and Curvularia pallescence have been evaluated. The screening results have been correlated with the structural features of the tested compounds. Organophosphorus derivatives containing 1,4-bis(4-chlorobenzaldehyde)piperazine dithiosemicarbazone and 1,4-bis(4-methoxybenzaldehyde)piperazine dithiosemicarbazone proved to be more active than some prevalent commercial synthetic fungicides.
- Chandra, Ruchi,Pandey,Sengupta
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Read Online
- Tunable Redox Potential Photocatalyst: Aggregates of 2,3-Dicyanopyrazino Phenanthrene Derivatives for the Visible-Light-Induced α-Allylation of Amines
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This work highlights the tunable redox potential of 6,11-dibromo-2,3-dicyanopyrazinophenanthrene (DCPP3) aggregates, which can be formed through physical π-πstacking interactions with other DCPP3 monomers. Electrochemical and scanning electron microscopy showed that the reduction potential of [DCPP3]n aggregates could be increased by decreasing their size. The size of [DCPP3]n aggregates could be regulated by controlling the concentration of DCPP3 in an organic solvent. As such, a fundamental understanding of this tunable redox potential is essential for developing new materials for photocatalytic applications. The [DCPP3]n aggregates as a visible-light photocatalyst in combination with Pd catalysts in the visible-light-induced α-allylation of amines were used. This [DCPP3]n photocatalyst exhibits excellent photo- and electrochemical properties, including a remarkable visible-light absorption, long excited-state lifetime (16.6 μs), good triplet quantum yield (0.538), and high reduction potential (Ered([DCPP3]n/[DCPP3]n-) > -1.8 V vs SCE).
- Bao, Ming,He, Min,Wang, Yi,Yu, Xiaoqiang
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p. 14720 - 14731
(2021/11/16)
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- Ene-Yne Metathesis of Allylphosphonates and Allylphosphates: Synthesis of Phosphorus-Containing 1,3-Dienes
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A variety of ene-yne cross metathesis reactions were performed using unsaturated phosphonate and phosphate reagents, affording the corresponding phosphorylated 1,3-diene products in good to excellent yields. These difficult ene-yne metatheses employed a Grubbs catalyst bearing a cyclic amino alkyl carbene ligand. A variety of terminal alkynes of varying substitution underwent the reaction, and different phosphorus-containing alkenes were found to give the conjugated diene products in high yields. The resulting dienes were further transformed by Horner-type Wittig reactions and a Diels-Alder cycloaddition.
- Rohde, Laurence N.,Wild, Thérèse H.,Diver, Steven T.
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p. 1371 - 1384
(2021/02/05)
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- Quinoline derivatives, and preparation method and use thereof
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The invention belongs to the technical field of insecticides and acaricides, and particularly relates to quinoline derivatives, and a preparation method and a use thereof, and concretely provides compounds represented by formula (I), and stereoisomers, racemates, tautomers, isotope labels, oxynitrides, pharmaceutically acceptable salts or solvates thereof. The compounds of the formula (I) have an excellent activity against various pests and pest mites in the agricultural field or other fields. The compounds can achieve an excellent control effect at a very low dosage, so the compounds can be used to prepare insecticides and/or acaricides. In addition, the preparation steps of the compounds of the invention are simple, and the product yield is high, so that the compounds have a good application prospect.
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Paragraph 0232-0234
(2019/10/17)
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- Phosphate ionic liquids as well as synthetic method and application thereof
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The invention discloses phosphate ionic liquids, a synthetic method thereof and an application as a lithium extraction agent. According to the method, the functional ionic liquids containing phosphamide groups are prepared from dibutyl phosphite, trichloroisocyanuric acid, N,N'-dimethylethanediamine and potassium hexafluorophosphate taken as raw materials through phosphoryl chlorination reaction,amidation with amine, salt forming reaction and exchange reaction. Compared with the prior art, the ionic liquids and the synthetic method thereof have the characteristics that operation is simple, industrial popularization and application are facilitated and the like, and have important application values.
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Paragraph 0027; 0028
(2018/05/16)
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- Eco-Friendly and Industrially Scalable Synthesis of the Sex Pheromone of Lobesia botrana. Important Progress for the Eco-Protection of Vineyard
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A one-pot synthesis of the pheromone of Lobesia botrana is described. The procedure allows an efficient and economical access to this product which is used for the protection of vineyards.
- Cahiez, Gérard,Guerret, Olivier,Moyeux, Alban,Dufour, Samuel,Lefevre, Nicolas
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supporting information
p. 1542 - 1546
(2017/10/25)
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- A single-step one pot synthesis of O,O′-dialkyl N,N-dialkylphosphoramidates from dialkylphosphites
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An efficient synthetic method has been developed to obtain chemical weapons convention (CWC)-related O,O′-dialkyl-N,N-dialkylphosphoramidates from dialkylphosphites using inorganic reagents (CuCl2and Cs2CO3) at room temperature.
- Purohit, Ajay Kumar,Pardasani, Deepak,Kumar, Ajeet,Goud, D. Raghavender,Jain, Rajiv,Dubey
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p. 3754 - 3756
(2016/07/26)
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- New benzotriazole-based reagents for the phosphonylation of various N-, O-, and S-nucleophiles
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Benzotriazole surrogates showing higher stabilities than the corresponding chlorophosphates, allow phosphonylation of a variety of N-, O-, and S-nucleophiles in good yields.
- Panmand, Deepak S.,Tiwari, Anand D.,Panda, Siva S.,Monbaliu, Jean-Christophe M.,Beagle, Lucas K.,Asiri, Abdullah M.,Stevens, Christian V.,Steel, Peter J.,Hall, C. Dennis,Katritzky, Alan R.
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supporting information
p. 5898 - 5901
(2015/01/08)
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- Synthesis of flame-retardant phosphaphenanthrene derivatives with high phosphorus contents
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Two novel types of phosphate derivatives of phosphaphenanthrene with a high phosphorus content were prepared by phosphorylation reaction between either 2-(6-oxido-6H-dibenzc,e1,2oxaphosphorin-6-yl)-methanol (ODOPM) or 2-(6-oxido-6H-dibenzc,e1,2.oxaphosphorin-6-yl)-1,4-benzenediol (ODOPB) and dialkyl phosphoryl chloride. The structures of all compounds were characterised by 1H NMR, 13C NMR, 31P NMR, Fourier transform infrared spectroscopy, and high-resolution mass spectrometry. The thermal stability of representative compounds was determined by thermal gravimetric analysis and differential scanning calorimetry. The results showed that the compounds have excellent resistance to oxidation, high thermal stability with an onset decomposition temperature above 200°C, and a high char yield over 25 %, owing to the high P content. The representative compound was added to conventional electrolytes of lithium-ion batteries as flame retardant additive, and the self-extinguishing time and ionic conductivity were measured. The result showed that the compounds have effective flame retardant properties.
- Zheng, Jinyun,Yu, Yujian,Zhang, Lulu,Zhen, Xiaomin,Zhao, Yufen
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p. 1688 - 1692
(2015/01/09)
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- Synthesis of phosphoramidates: A facile approach based on the C-N bond formation via Ir-catalyzed direct C-H amidation
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A new synthetic route to phosphoramidates by intermolecular C-H amidation is presented. Substrates with assorted directing groups were activated by an iridium-based catalyst system and reacted with a number of phosphoryl azides, executing efficient phosphoramidate synthesis via C-N bond formations. (Chemical Equation Presented).
- Kim, Hyunwoo,Park, Juhyeon,Kim, Jeung Gon,Chang, Sukbok
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supporting information
p. 5466 - 5469
(2015/01/09)
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- Design and synthesis of novel active phosphonate esters and their application in preparation of ceftriaxone
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For a series of active phosphonate esters, the anhydride abbreviated as ANPTA (6a) exhibits the highest reactivity in the preparation of ceftriaxone. The synthesis of ceftriaxone was optimized with the pilot-scale yield reaching 95.7%. The results were explained from the structural viewpoint and supported by analysis of the calculated Mulliken atomic charge distribution.
- Ren, Hui-Xue,Sun, You-Min,Wu, Dao-Ji,Ma, Yong-Shan,Ying, Han-Jie,Ma, Yan
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p. 155 - 159
(2014/07/07)
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- Synthesis, structures, and fungitoxicity of novel organophosphorus compounds
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A series of biologically active organophosphorus compounds have been synthesized by the reactions of O,O-diethylchlorophosphate with Schiff bases derived from 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-oxadiazole and salicylaldehyde/2-hydroxyacetophenone. The compounds have been characterized on the basis of analyses and spectral (IR, 1H, 13C NMR) data. Fungicidal activities of these derivatives against Colletotrichum falcatum, Fusarium oxysporum, and Curvularia pallescence have been evaluated. All compounds showed moderate to significant antifungal activity.
- Pandey, Venkatesh K.,Chaturvedi, Kalpana,Chandra, Ruchi,Pandey, Om P.,Sengupta, Soumitra K.
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p. 1401 - 1408
(2012/11/07)
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- Distribution and elimination of 14C-ethion insecticide in chamomile flowers and oil
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The residual fate of 14C-ethion labeled at the ethyl group in chamomile flowers and oil was studied. 14C-ethion and some of its degradation products have been prepared for the present investigation. 14C-residues in its flowers and oil were determined at different time intervals. Chromatographic analysis of chamomile oil extracts revealed the presence of the parent compound together with four metabolites, which were identified as ethion monooxon, ethion dioxon, O,O-diethyl phosphorothioate, and O-ethyl phosphorothioate. Effect of drying on ethion residues in chamomile flowers was investigated. Ethion residues were decreased by sun drying of chamomile flowers. The percentage of removal was 18%-47%. Effect of using low cost adsorbents for removal of ethion residues from chamomile oil was investigated. The removal percentage due to adsorption was 100% for CaO and saw dust adsorbers and for watermelon peels, bagass, and rice bran adsorbers were 36%, 41%, and 90%, respectively. Our results proved that the addition of CaO saw dust and rice bran reduced the pesticide residues, so we recommend the addition of these adsorbents during the extraction process to reduce the risk of pesticide residues on chamomile oil. Copyright Taylor & Francis Group, LLC.
- Abdel-Gawad,Abdelhameed,Elmesalamy,Hegazi
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supporting information; experimental part
p. 2122 - 2134
(2011/12/02)
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- METAL COMPLEX COMPOUND, CANCER THERAPEUTIC COMPOSITION COMPRISING THE METAL COMPLEX COMPOUND AS ACTIVE INGREDIENT, AND INTERMEDIATE FOR PRODUCTION OF THE METAL COMPLEX COMPOUND
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A metal complex compound which exhibits a high degree of adsorption to bone or inhibition of cell growth, and is highly effective for therapy of a cancer metastasized to bone and therapy of the primary carcinoma thereof; a therapeutic agent composition for a cancer containing as an active ingredient the metal complex compound or a physiologically acceptable salt thereof; and an intermediate for the metal complex compound are provided. More concretely, a metal complex compound represented by the following General Formula (1): (wherein R1 independently represents C1-C10 alkyl which may be branched or have a substituent; or a C3-C30 cyclic group which may have a substituent; and X represents CHR2, an oxygen atom or NR5); a therapeutic agent composition for a cancer containing it as an active ingredient; and an intermediate for the metal complex compound are provided.
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Page/Page column 24-25
(2010/05/13)
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- N,N-Dichloro poly(styrene-co-divinyl benzene) sulfonamide polymeric beads: an efficient and recyclable reagent for the synthesis of dialkyl chlorophosphates from dialkylphosphites at room temperature
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An efficient and operationally simple method is developed for the synthesis of dialkyl chlorophosphates from dialkylphosphites using a new chlorine bearing reagent, N,N-dichloro poly(styrene-co-divinyl benzene) sulfonamide in the form of polymeric beads. The reagent afforded dialkyl chlorophosphates at room temperature, and is recyclable.
- Gupta, Hemendra K.,Mazumder, Avik,Garg, Prabhat,Gutch, Pranav K.,Dubey, Devendra K.
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scheme or table
p. 6704 - 6706
(2009/04/07)
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- Trichlorocyanuric acid: An efficient reagent for one-pot synthesis of Ptychodiscus brevis (PB-1) toxin and its derivatives
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Trichlorocyanuric acid is an efficient regent for simple and one-pot synthesis of dialkyl, N-cycloctylphosphoraamidates (PB-1) and its various derivatives in excellent yields. The procedure is operationally simple and involves the reaction of various dialkylphosphites with trichloroisocyanuric acid in acetonitrile and subsequent treatment with amines in presence KF-celite to give PB-1 and derivatives.
- Gupta, Arvind K.,Acharya, Jyotiranjan,Dubey, Devendra K.,Kaushik, Mahabir P.
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- Efficient and convenient one-pot synthesis of phosphoramidates and phosphates
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A simple and efficient one-pot method is described for the synthesis of phosphoramidates/phosphates in excellent yields from dialkylphosphites and trichloroisocyanuric acid in acetonitrile and subsequent treatment with dialkyl amines/alcohols. The procedure is operationally simple, has reduced reaction times, and uses a one-pot procedure. Copyright Taylor & Francis Group, LLC.
- Gupta,Acharya,Dubey,Kaushik
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p. 3403 - 3407
(2008/02/13)
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- N,N′-dichlorobis(2,4,6-trichlorophenyl)urea (CC-2): An efficient reagent for the synthesis of chemical weapons convention-related dialkyl-N,N-dialkylphosphoramidates from dialkylphosphites
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The present paper describes the one-pot synthesis of dialkyl N,N-dialkylphosphoramidates (DADAP) from dialkylphosphites and dialkylamines using N,N?-dichlorobis(2,4,6-trichlorophenyl)urea (CC-2) as chlorinating reagent. DADAP belong to the schedule 2.B.6 category of the Chemical Weapons Convention (CWC), as they are the important markers of the chemical warfare agent tabun and its analogues. The study was undertaken to develop the spectral database of DADAP for verification of CWC. The reported synthetic strategy can be adopted to rapidly synthesize several analogues of DADAP during official proficiency tests. CSIRO 2007.
- Gupta, Arvind K.,Pardasani, Deepak,Gupta, Hemendra K.,Dubey, Devendra K.
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p. 879 - 882
(2008/09/16)
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- N-tert-butyl-N-chlorocyanamide: A mild and efficient chlorinating agent for the synthesis of dialkyl/diaryl chlorophosphates
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An efficient reagent for the synthesis of dialkyl/diaryl chlorophosphates has been developed. N-tert-Butyl-N-chlorocyanamide acts as a chlorinating agent both in polar as well in non-polar medium and the transformation of dialkyl/diaryl phosphites to the dialkyl/diaryl chlorophosphates takes place rapidly under mild conditions in quantitative yields. Copyright
- Kumar, Vinod,Kaushik, Mahabir Parshad
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p. 312 - 313
(2007/10/03)
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- Trichloroisocyanuric acid: An efficient reagent for the synthesis of dialkyl chlorophosphates from dialkyl phosphites
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A mild and operationally simple method for the synthesis of dialkyl chlorophosphates is described. Trichloroisocyanuric acid is used as an effective reagent for the rapid conversion of dialkyl phosphites to their corresponding dialkyl chlorophosphates under mild conditions.
- Acharya,Gupta,Shakya,Kaushik
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p. 5293 - 5295
(2007/10/03)
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- N, N′-Dichloro bis(2,4,6-trichlorophenyl) urea (CC-2): An efficient reagent for synthesis of dialkyl chlorophosphates
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An efficient and simple method is described for the preparation of dialkyl chlorophosphates by the use of new positive chlorine bearing reagent namely N,N′-dichloro bis(2,4,6-trichlorophenyl) urea.
- Shakya,Dubey,Pardasani, Deepak,Palit, Meehir,Gupta
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p. 821 - 823
(2007/10/03)
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- Reaction of chlorides of phosphoric, sulfonic, and carboxylic acids on solid potassium carbonate surface under PTC circumstances
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Simple syntheses of phosphoric (4) and carboxylic (6) acid anhydrides have been elaborated by means of solid potassium carbonate in phase-transfer catalytic acylation. Behavior of various acid chlorides, phosphoric (1), sulfonic (2), and carboxylic (8), have also been studied toward potassium carbonate in the presence of lipophilic quaternary ammonium salt.
- Jaszay, Zsuzsa M.,Petnehazy, Imre,Toe, Laszlo
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p. 447 - 450
(2007/10/03)
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- Studies on the interaction of phosphine selenides and their structural analogues wth dihalogens and sulfuryl chloride
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The phosphine selenides, tris(dimethylamino)phosphine selenide, esters of selenophosphoric acid, and esters of selenophosphonic acid react with dihalogens and sulfuryl chloride to form halogenoselenophosphonium salts (≡ 3P-SeX)+X-. T
- Krawczyk, Ewa,Skowronska, Aleksandra,Michalski, Jan
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p. 4471 - 4478
(2007/10/03)
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- Tricyclic triazolobenzazepine derivatives, process for producing the same, and antiallergic
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Tricyclic triazolobenzazepine derivatives in the form or a prodrug are provided. The compounds according to the present invention are those represented by formula (I) and pharmacologically acceptable salts and solvates thereof. The compounds are useful as antiallergic agents and exhibit excellent bioavailability. wherein R1 represents hydrogen, OH, alkyl or phenyl alkyl,R2, R3, R4, and R5 represent hydrogen, halogen, optionally protected hydroxyl, formyl, optionally substituted alkyl, alkenyl, alkoxy or the like, andQ represents a group selected from the following groups (i) to (iv), halogen, or alkoxy:
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- Hydrolysis of phosphotriesters: Determination of transition states in parallel reactions by heavy-atom isotope effects
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The remote label method was used to measure primary and secondary 18O isotope effects in the alkaline hydrolysis of O,O-diethylphosphorylcholine iodide (DEPC) and the primary 18O effect in the alkaline hydrolysis of O,O-diethyl-m-nitrobenzyl phosphate (DEmNBP). Both the leaving group of interest (choline or m-nitrobenzyl alcohol) and ethanol can be ejected during hydrolysis due to the similarity of their pK values. The heavy-atom isotope effects were measured by isotope ratio mass spectrometry. Parallel reaction and incomplete labeling corrections were made for both systems. DEPC has a primary 18O isotope effect of 1.041 ± 0.003 and a secondary 18O isotope effect of 1.033 ± 0.002. The primary 18O isotope effect for DEmNBP was 1.052 ± 0.003. These large effects suggest a highly associative transition state in which the nucleophile approaches very close to the phosphorus atom to eject the leaving group. The large values are also indicative of a large compression, or general movement, on the reaction coordinate.
- Anderson,Shim,Raushel,Cleland
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p. 9246 - 9253
(2007/10/03)
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- A new polymeric flame retardant additive for vinyl polymers
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Diethyl allyl phosphate (DEAP) monomer has been synthesized, and characterized, using 1H NMR and direct ionization mass spectrometric (DI-MS) techniques. It was free-radically polymerized to yield the poly(diethyl allyl phosphate) (PDEAP). The direct pyrolysis-mass spectrometric (DP-MS) analysis of the PDEAP revealed that it undergoes thermal degradation to yield mainly the monomer. Utility of PDEAP as a potent flame-retardant additive in polystyrene (PS) and poly(methyl methacrylate) (PMMA) has also been established.
- Sundarrajan,Kishore,Ganesh
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- Metallo-phosphorylation of olefins: Reaction of diethyl chlorophosphate with Zirconocene-ethylene complex
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Zirconocene-ethylene complex Cp2Zr (CH2 = CH2) reacted with chlorophosphate to form zircono-ethylphosphonate, which could be converted into various functionalized ethylphosphonates.
- Xi,Ma,Li
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p. 2554 - 2555
(2007/10/03)
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- Reaction of Trichloro(o-phenylenedioxy)phosphorane with Four-Coordinate Phosphorus Esters
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Reactions of trialkyl phosphates and dialkyl alkenylphosphonates with trichloro(o-phenylenedioxy)phosphorane result in selective replacement of one alkoxy group on the phosphorus by a chlorine atom. Alkylphosphonates react with trichloro(o-phenylenedioxy)phosphorane to give alkyl alkylphosphonochloridates as the major products and small amounts of alkylphosphonic dichlorides.
- Khusainova,Reshetkova,Cherkasov
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p. 367 - 369
(2007/10/03)
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- Ethyl octylphosphonofluoridate and analogs: Optimized inhibitors of neuropathy target esterase
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The relation between organophosphorus-induced delayed neuropathy (OPIDN) and brain neuropathy target esterase (NTE) inhibition is further examined in hens by structure-activity studies leading to the most potent in vitro NTE inhibitors known, which are then examined for their neuropathic effects in vivo in hens. The principal compounds studied are alkyl alkylphosphonofluoridates and dialkyl phosphorofluoridates. Potencies that exceed those of any previous inhibitors under the standard in vitro NTE assay condition are achieved with alkyl octylphosphonofluoridates (ethyl, isopropyl, 2-chloroethyl, 2-bromoethyl, 2-iodoethyl, and 3-iodopropyl), 2-iodoethyl hexylphosphonofluoridate, and dialkyl phosphorofluoridates [ethyl, nonyl; di(2-iodoethyl); di(3-iodopropyl); dipentyl]. The concentration for 50% NTE inhibition (I50) of these compounds is 0.04-0.14 nM. Thirty-eight less active analogs including aryl phosphonates and aryl phosphates give I50s of 0.27-4730 nM. For highest potency the summation of length of the alkyl and alkoxy groups on phosphorus should be 12-16 atoms (carbons, oxygens, and phosphorus) (a terminal iodo substituent in this relationship is equivalent to a propyl group). In general, the phosphonofluoridates and phosphorofluoridates are more active than analogs with leaving groups other than fluorine, i.e., phenoxy, 4-nitrophenoxy, 4-cyanophenoxy, 3,4-dichlorophenoxy, and 4H-1,3,2-benzodioxaphosphorin. Considering the exceptional potencies of ethyl and 2-iodoethyl octylphosphonofluoridates (I50s of 0.04 and 0.09 nM, respectively), it is not surprising that at ip doses of 10-30 mg/kg they inhibit brain NTE by 82-97% 48 h after treatment. However, unexpectedly, only the ethyl but not the 2-iodoethyl compound induces OPIDN, possibly associated with the greater ease of aging for NTE inhibited with the ethyl than the 2-iodoethyl compound (as observed in vitro both spontaneously and on induction by potassium fluoride). The high potency of ethyl octylphosphonofluoridate and several analogs as NTE inhibitors suggests that they are useful probes in determining the toxicological features of this secondary lesion for organophosphorus poisoning.
- Wu,Casida
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p. 1070 - 1076
(2007/10/03)
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- Tellurium tetrachloride as an efficient chlorinating agent for di- or trialkyl phosphites: Novel synthesis of dialkyl chlorophosphates
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Various dialkyl chlorophosphates are prepared by the reaction of TeCl4 with di- or trialkyl phosphites in good yields.
- Koh,Oh
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p. 1771 - 1774
(2007/10/02)
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- Reactions of Trico-ordinate Phosphorus Compounds with Phosphorus Pseudohalogens. Part 2. Pentaco-ordinate Intermediates in the Reaction of o-Phenylene Neopentyl Phosphite with Diethoxyoxophosphoranesulfenyl Chloride
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Reaction between oxophosphoranesulfenyl chloride 1 (R = R' = EtO) and o-phenylene neopentyl phosphite 4 takes predominantly the deoxygenation course, yielding the phosphorochloridothioate 7 and the phosphate 8.Formation of minor products 5 and 6 corresponding to the desulfurization pathway, and low-temperature 31P NMR observations, are rationalized by proposing phosphorane-phosphonium equilibria which are shifted towards phosphorane structures 9, 13, 11.These results supplement our earlier studies on desulfurization and deoxygenation of compound 1 with tricoordinate phosphorus compounds and add new evidence for phosphonium-phosphorane equilibria.
- Krawczyk, Ewa,Skowronska, Aleksandra,Michalski, Jan,Mikolajczak, Jerzy
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p. 851 - 854
(2007/10/02)
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- Reaction of Tricoordinate Phosphorus Compounds with Organophosphorus Pseudohalogens. 1. Desulfurization and Deoxygenation of Oxophosphoranesulfenyl Chlorides. Scope and Mechanism
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The reaction of oxophosphoranesulfenyl chlorides RR'P(O)SCl 2 with PIII compounds has been investigated.Its mechanistic features have been elucidated by variable-temperature 31P NMR spectroscopy and stereochemical changes at PIV and PIII phosphorus centers.These studies show that in all cases phosphonium intermediates containing the sulfur bridge >P(O)-S-P(+)P(S)-O-P(+)-Cl(-).The latter decomposes by the attack of the chloride anion on the thiophosphoryl center (deoxygenation pathway). 31P NMR studies fully corroborated the observed stereochemical changes.
- Krawczyk, E.,Mikolajczak, J.,Skowronska, A.,Michalski, J.
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p. 4963 - 4970
(2007/10/02)
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- Reaction of Thiolo and Selenolo Esters of Phosphorus Acids with Halogens. Part 3. Interaction of O,O,S-Trialkyl Phosphorothioates and O,S-Dialkyl t-Butylphosphonothioates with Sulphuryl Chloride and Halogens
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The reaction of the title phosphono- and phosphoro-thiolates with sulphuryl chloride and halogens involves in every case the formation of intermediates containing two phosphorus atoms >P+(SR)OP(O)- (X = SO2Cl or halogen).The formation of the latter in the course of chlorinolysis of phosphorus thiolesters is suggested to be responsible for the occurrence of a mechanism involving retention of configuration.The effect of the structure of the reactants and the nature of solvent on the reaction stereochemistry is discussed.
- Krawiecka, Bozena,Wojna-Tadeusiak, Elzbieta
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p. 229 - 237
(2007/10/02)
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- HALOGENOPHILIC REACTION OF SILYLATED PHOSPHITES WITH TRICHLOROACETIC ACID DERIVATIVES
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Silylated phosphites and amidophosphites react with trichloroacetonitrile and ethyl trichloroacetate with the formation of a P-Cl bond, which indicates a halogenophilic mechanism of the reaction.
- Lermontov, S. A.,Zavorin, S. I.,Sukhozhenko, I. I.,Pushin, A. N.,Martynov, I. V.
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p. 404 - 408
(2007/10/02)
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- DIREKTSYNTHESE VON N,N-DIORGANYL-PHOSPHORSAEUREDIALKYLESTERAMIDEN AUS TRIALKYLPHOSPHITEN
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Dialkyl N,N-Diorganylphosphoroamidates result in the reaction of trialkylphosphites with secondary amines and tetrachlormethane if amine hydrochlorides are used as catalysts.A reaction mechanism is proposed.Key words: N,N-Diorganylphosphoroamidates; trialkylphosphites; tetrachlormethane.
- Albrecht, Steffen,Herrmann, Eckhard
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p. 189 - 192
(2007/10/02)
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- NEW CHEMISTRY AND STEREOCHEMISTRY OF ORGANOPHOSPHORUS PSEUDOHALOGENS
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Synthesis, chemistry and stereochemistry of organophosphorus-sulfur(selenium)pseudohalogens are discussed and rationalized.
- Michalski, Jan,Skowronska, Aleksandra,Lopusinski, Andrzej
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- REACTIVITY OF TRIETHYL PHOSPHITE WITH TETRACHLOROMETHANE : ELECTRON TRANSFER VERSUS IONIC SUBSTITUTION ON "POSITIVE" HALOGEN
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The reaction of triethyl phosphite (1) with tetrachloromethane (2) has been studied from a mechanistic point of view. 1 reacts at 80 deg C with 2 to form diethyltrichloromethanephosphonate (3) (85-90percent yield) and chloroethane (4) (80percent yield).Several results hint at a radical chain mechanism (like SRN1).Trichloromethyl radical is trapped by 2,6-di-t-butyl-4-cresol (BHT), the reaction may be initiated with UV radiation (254 nm) and a charge transfer complex (CTC) is formed between 1 and 2 ; furthermore, the reaction is inhibited by 7,7',8,8' tetracyanoquinodimethane (TCNQ).Tris(cyclopropylmethyl)phosphite (12a) and tri(1-hexene-6-yl) phosphite (7a) are used as potential radical clocks in these reactions.The first leads inter alia to 3-chloro-1-butene (17) and the second to 5-chloro-1-hexene (11), the first therefore suggests a radical mechanism but not the second.However in this particular case even the results obtained with the tris(cyclopropylmethyl)phosphite may be rationalized also by an ionic mechanism.For the photostimulated reaction , the overall quantum yield is 0.1.The electrochemical oxidation of 1 with added CCl4 does not account for a radical chain process as the main pathway.Furthermore, the application of Marcus analysis to reaction viewed as an electron transfer leads to a calculated rate constant in the range of 10-20 M-1s-1.The synergy of the techniques that we used lead us to conclude that the thermal reaction is in fact an SNCl+ substitution.The radical intermediates would mainly be derived from the electron-transfer reaction between CCl3- and CCl4 the importance of which increases when special conditions such as hν activation are applied.Reaction therefore provides an example where the observed paramagnetic species during a D/A interaction could deceptively suggest an electron-transfer between D and A whereas they originate from an interaction between A and an electron donor formed after or during the first step of the reaction.
- Bakkas, Salem,Julliard, Michel,Chanon, Michel
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p. 501 - 512
(2007/10/02)
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- Nucleoside Phosphonates: Part 7. Studies on the Oxidation of Nucleoside Phosphonate Esters
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Oxidation of phosphonate mono- and di-esters with various oxidizing agents including diaryl disulphides, hexacloroacetone, and iodine, has been investigated under various reaction conditions.The most efficient oxidation procedure consists of treatment of phosphonate esters with iodine in pyridine-water.When the phosphonate esters were presilylated by treatment with trimethylsilyl chloride, the subsequent oxidation with aqueous iodine was faster. (31)P N.m.r. spectroscopic studies have enabled us to propose the most likely pathway for the majority of the oxidations.
- Garegg, Per J.,Regberg, Tor,Stawinski, Jacek,Stroemberg, Roger
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p. 1269 - 1274
(2007/10/02)
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- HYDROLYSE BASIQUE COMPAREE D'ESTERS ALLOPHANIQUES ET PHOSPHORIQUES EN MILIEU MIXTE ACETONITRILE/EAU FAIBLEMENT AQUEUX; MISE EN EVIDENCE D'UNE ENTITE CATALIQUE, INTERMEDIARE DE LA REACTION ENTRE BASE ET SOLVANT
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Kinetic study of base catalysed hydrolysis in acetonitrile-water mixtures of allophanic esters (models of carboxybiotine) and phosphoric esters shows in the range of low water content (less than 1 molar) an enhancement in rate (103) with a maximum at 0.1-0.3 molar in water.This rate enhancement is ascribed to ground state desolvation and the maximum is interpreted by a change in the rate determining step: leaving group departure in the tetrahedral intermediate is indeed the slow step for the reactions in acetonitrile/water mixture less than 0.1 molar in water.For charged phosphoric esters the rate enhancement from an aqueous medium (pH=10) to organic is larger since as high as 106.On the other hand, in such a medium, an additional catalytic effect is observed; it is shown that it is due to the formation of a reactive species which results from reaction of the base on acetamide when accumulated in the medium from base catalysed hydrolysis of the solvent.
- Monnier, Par E.,Botella, J. M.,Murillo, A.,Klaebe, A.,Perie, J.
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p. 1315 - 1332
(2007/10/02)
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- N,N-DIHALOPHOSPHORAMIDES - XVI IONIC ADDITION OF DIETHYL N,N-DIBROMOPHOSPHOROAMIDATE (DBPA) TO ALKENES AND CYCLOALKENES
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The addition of DBPA to a variety of phenylethylenes, straight-chain terminal and nonterminal alkenes as well as cycloalkenes in the presence of boron trifluoride etherate has been investigated.It was found that the reaction proceeds smoothly at -20 deg C by adding an olefin to the solution of equimolar amounts of DBPA and boron trifluoride etherate in tetrachloromethane.N-Bromoadducts (mixtures or single isomers depending upon the structure of the olefin) initially formed could be reduced in situ with sodium bisulphite solution to give the corresponding diethyl N-(β-bromoalkyl)phosphoroamidates which in turn afforded β-bromoamine hydrochlorides upon treatment with hydrogen chloride in benzene at room temperature.The regiospecificity typical for Markovnikov addition, as proven by NMR and MS evidence, was observed for unsymmetrical phenylethylenes.The addition of DBPA to (E)-1-phenylpropene, (E)-2-butene, and (Z)-2-butene was also found to proceed stereospecifically affording the corresponding anti-adducts.These results are fully compatible with an ionic addition pathway and can be rationalized by assuming the intermediate formation of an electrophilic complex between DBPA and boron trifluoride.The reaction offers a new approach to aminobromination of alkenes and cycloalkenes and makes possible an easy access to β-bromoamines, the convenient precursors of aziridines.
- Osowska-Pacewicka, K.,Zwierzak, A.
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p. 4717 - 4726
(2007/10/02)
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