Phosphorus Esters Research Articles

Acute toxicity of bicyclic phosphorus esters.

The acute toxicity of 4-ethyl-1-phospha-2,6,7-trioxabicyclo (2.2.2) octane-1-oxide and 4-ethyl-1-phospha-2,6,7-trioxabicyclo (2.2.2) octane has been determined by different routes of application in various species of animals. The compounds stimulate the activity of the central nervous system and are highly toxic. They showed no toxic cumulative effects. The presence of the bicyclic phosphate ester in the combustion products of specific rigid polyurethane foams is discussed. The question is raised whether there may be an additional hazard caused by this combustion product in a real fire situation.

Studies on the Thermal Degradation of Phosphorus-Containing Polymers

Information is given to explain how phosphorus compounds contribute to flame retardance of cotton. The fabric treated with the following retardants can be expected to have effective flame retardance: (1) Phosphorus compounds are in ester-linkage with cellulose chains or are able to esterify with cellulose during pyrolysis. (2) The phosphorus ester groups introduced into cellulose chains are eliminated readily and conjugated double bonds are formed. The ease of formation of double bonds is due to the electron density in the phosphoryl group. The effect of the increase of its electron density leads to an increase of efficiency of flame retardance.

Mechanism of the reaction between trialkyl phosphates and dialkyl phosphorochloridates: nucleophilic sites in phosphorus(V) esters

Reaction between the phosphate 2-methoxy-5,5-dimethyl-1,3,2-dioxaphosphorinan-2-one (Ia), labelled with 18O in the phosphoryl group, and the phosphorochloridate 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphorinan-2-one (II), to give the labelled pyrophosphate 2,2′-oxybis-(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-one)(III) shows that the reaction proceeds through nucleophilic attack on the chloridate by both the methoxy and the phosphoryl oxygen atoms of the phosphate. The former route is probably rather more important than the latter.

Stereospecific synthesis from carbohydrate precurors of (R)- and (S)-ethyl isopropyl methyl phosphate and other optically active neutral phosphorus esters

Stereospecific syntheses starting from carbo-hydrate precursors of (+)-(R) and (–)-(S)-ethyl iso-propyl methyl phosphates, (+)-(R)-O-ethyl O,S-dimethyl phosphorothioate, and (+)-(R)-ethyl methyl methyl-phosphonate are described; the enantiomeric purity of these compounds was determined by an n.m.r. method involving the use of tris-[3-(heptafluoro-n-propylhydroxy-methylene)-(+)-camphorato]europium(III).

Pentacovalent intermediate in the Arbuzov reaction

Direct evidence by 31P-n.m.r. spectroscopy is presented for the formation of a five-co-ordinate intermediate in the Arbuzov reaction of tervalent phosphorus esters with elemental chlorine or elemental bromine and benzenesulphenyl chloride.

Studies on the thermal degradation of phosphorus containing polymers: 7. Thermal degradation of phosphorylated poly(vinyl alcohol)

The thermal degradation of phosphorylated poly(vinyl alcohol) was investigated using thermogravimetric analysis, infra-red spectroscopy and gas chromatography. The introduction of phosphoric acid groups changed the course of the thermal degradation of the polymer. The dehydration was accelerated and the scission of the polymer chain was inhibited. The cis-β-elimination mechanism of the phosphorus ester group was proposed for the accelerated dehydration.

Metabolism of Salithion (2-methoxy-4H-1,3,2-benzodioxaphosphorin-2-sulfide) in rats and plants.

Metabolism of an organophosphorus insecticide, Salithion® (2-methoxy-4H-1, 3, 2-benzodioxaphosphorin-2-sulfide), in male rats, rice plants and bean plants was studied by using the carbon-14 labeled compound at the benzyl carbon. At the dosage of 9mg/kg, 82.0% of the radiocarbon were excreted in urine within 24 hr after oral administration to male rats. The administered radiocarbon was recovered majorly into urine during one week. When the dosage level was increased to 45mg/kg or when 9mg/kg of Salithion was consecutively given 5 times, the radiocarbon was also rapidly excreted and substantially completely recovered majorly into urine. No radioactive CO2 was expired. In the urine, at least 15 radioactive metabolites were detected by thin-layer chromatography (tlc), among which the following seven compounds were identified by cochromatography with the authentic compounds and IR, NMR spectroscopy; O-(2-hydroxy) benzyl dihydrogen phosphate, desmethyl salioxon, O-(2-hydroxy) benzyl dihydrogen phosphorothioate, desmethyl salithion, salioxon, saligenin and Salithion, and the major one was desmethyl salithion. The intact Salithion was negligible. Most of 14C-Salithion applied on bean plants and rice plants were vaporized and Salithion incorporated into plants underwent the cleavage of the cyclic phosphorus ester group to give saligenin which was conjugated with glucose at the benzyl-OH and phenol-OH (salicin). Except the above conjugates all the radioactive metabolites were included in those in rats urine. In bean plants, Salithion and desmethyl salithion were also found.

Synthesis and insecticidal properties of some 2‐substituted‐3‐oxo‐4‐halo‐5(2H)‐pyridazinyl phosphorus esters

AbstractA series of novel esters of organophosphorus compounds were prepared from 2‐substituted‐4‐halo‐5‐hydroxy‐3(2H)‐pyridazinone and their insecticidal effects were studied. Many of the compounds prepared showed insecticidal and acaricidal contact activity.

Persistence, Mobility, and Degradation of14C-Dimethoate in Soils

Dimethoate-carbonyl-14C was applied to 3 types of soil (silty loam, loamy sand, and clay loam) contained in 10-inch-diameter cylinders sunk into the ground to give concentrations in the top one inch of 0.056 and 0.169 ppm in 2 separate experiments. Thereafter, samples were taken periodically, extracted, fractionated, and analyzed for residues of dimethoate and its metabolites. The same metabolites were found in all 3 soil types, although in varying quantities. Dimethoate was converted to its oxygen analogue and 2 unknown metabolites. Conversion to dimethoxon was faster in the more moist soils, and levels were generally greater. Dimethoate carboxylic acid was the only hydrolytic metabolite identified. No major difference in total recovery of applied radioactivity was noted between the 3 soil types. However, less radioactivity was recovered from all soils in the 2nd set of experiments where more moist soils were encountered. The ratios between radio-activity recovered in the chloroform and water fractions and the unextracted soil residues were relatively constant in all 3 soil types in both experiments. Distribution of radioactivity appeared to be influenced somewhat by soil type. Downward movement was slightly more extensive in the loamy sand soil. Increased soil moisture content also promoted downward movement in all 3 soil types and more rapid disappearance of the dimethoate-14C-equivalents. The quantity of unextracted radioactivity remaining in the soil was not significantly different between the 3 soil types. The nature of these soil residues, accounting for a high proportion of the applied dose, remains unknown. It was established that these materials are not neutral phosphorus esters.

Total dealkylation of esters of trivalent phosphorus and promotion of anhydride formation by N,N,N',N'-tetramethylchloroformamidinium chloride

Total dealkylation of esters of trivalent phosphorus and promotion of anhydride formation by N,N,N',N'-tetramethylchloroformamidinium chloride

IODINATED THYROLIPIDS

ABSTRACT Sheep, bovine, mouse, dog and human thyroids incorporate 35–55% (41.5%, 45.9%, 34.4%, 55.4% and 41.1%, respectively) of total lipid radiodine in an unidentified polar thyrolipid fraction moving between phosphatidyl ethanolamine and phosphatidic acid on silica gel G thin layer chromatography in a solvent system CHCl3:MeOH:H2O (80:25:3). This unidentified lipid fraction (Fr. II) is ninhydrin negative, phosphorus negative, alkali labile, acid stable, phospholiphase A stable and orcinol positive indicating the absence of a free amino group, phosphorus group, vinyl ether linkage, vicinal phosphorus ester linkage and the presence of a sugar moiety. Iodination of fraction II seems to be specific for the thyroid gland only, as the other iodide concentrating tissues such as the submaxillary salivary gland and stomach localise most of the radioiodine with phosphatidyl choline and lyso-phosphatidyl ethanolamine fraction respectively. Biologically inactive thyroid tissue or non-enzymic iodination of isolated thyrolipids indicate phosphatidyl choline and/or phosphatidyl ethanolamine as major iodinated lipid fractions. The possible role of fraction II in iodination for homornogenesis in thyroid tissue is discussed.

Reactions of tert-butyl peresters. XI. Reactions of alkyl tert-butylperoxy alkylphosphonates, dialkyl tert-butylperoxy phosphates, and other phosphorus esters with benzene and aluminum chloride, and reactions of dialkyl tert-butylperoxy phosphates with phenylmagnesium bromide

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReactions of tert-butyl peresters. XI. Reactions of alkyl tert-butylperoxy alkylphosphonates, dialkyl tert-butylperoxy phosphates, and other phosphorus esters with benzene and aluminum chloride, and reactions of dialkyl tert-butylperoxy phosphates with phenylmagnesium bromideG. Sosnovsky, E. H. Zaret, and M. KoniecznyCite this: J. Org. Chem. 1972, 37, 14, 2267–2272Publication Date (Print):July 1, 1972Publication History Published online1 May 2002Published inissue 1 July 1972https://doi.org/10.1021/jo00979a013RIGHTS & PERMISSIONSArticle Views76Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (764 KB) Get e-Alerts Get e-Alerts

Steric and electronic effects on the stereochemistry of the alkaline hydrolysis of acyclic dialkoxyphosphonium salts. Pseudorotation of intermediates in phosphorus ester reactions

Steric and electronic effects on the stereochemistry of the alkaline hydrolysis of acyclic dialkoxyphosphonium salts. Pseudorotation of intermediates in phosphorus ester reactions

Nature of neutral phosphorus ester metabolites of phosphamidon formed in rats and liver microsomes.

Nature of neutral phosphorus ester metabolites of phosphamidon formed in rats and liver microsomes.

Biochemical and behavioural effects of some halo-substituted vinyl phosphorus esters

Biochemical and behavioural effects of some halo-substituted vinyl phosphorus esters

Coupling Agents as Adhesion Promoters

ABSTRACT An extensive review has been made of the literature from 1950 to the present to include all work in the area of coupling agents and their use toward improving adhesion. The types of agents studied, mechanisms by which they act, substrates, adhesive systems, and theories of adhesion are all considered. By far the most common system is silane agent on a glass substrate, and a covalent siloxane linkage is proposed as the operative mechanism. Phosphorus esters and chromium-acid complexes are also known to be effective, and similar mechanisms are postulated. Other species will adsorb on adherend surfaces to provide an adhesive interlayer. The use of coupling agents as admixtures with adhesives and the use and mechanisms of their behavior on metallic substrates have not been thoroughly studied until recently.

Cyclic organophosphorus compounds. Part XIII. Stereospecific formation of 4-substituted 1,3,2-dioxaphosph(V)orinans from bicyclic phosphorus(III) esters

2,7,8-Trioxa-1-phosphabicyclo[3,2,1]octane and its 4,4-dimethyl derivative have been prepared by transesterification. Both compounds undergo stereospecific ring opening when treated with benzyl or triphenylmethyl chlorides, methyl toluene-p-sulphonate, N-chloropiperidine, or N-chloromorpholine. Attempts to prepare 2,6,7-trioxa-1-phosphabicyclo[2,2,1]heptane have been unsuccessful.

Chlorine nuclear quadrupole resonance of phosphorus–chlorine compounds

The 35Cl n.q.r. frequencies at 77 K of two chloro(phenyl)phosphoranes, four cyclic phosphorus esters, four phosphoryl and thiophosphoryl chlorides, and eight chlorophosphates, are reported. The frequencies are used to predict possible molecular structures, and are related to σ- and π-bond effects within the molecules, by use of BEEM.

Reactions of phosphorus esters with phenylmagnesium bromide

Reactions of phosphorus esters with phenylmagnesium bromide

The 1H and 31P NMR spectrum of 1-phospha-2,6,7-trioxabicyclo[2.2.1]heptane

Analysis of the 60- and 100-MHz 1H NMR spectra of the title bicyclic phosphorus ester as an AA′BB′KX spin system (where AA′BB′ represents the four CH 2 protons, K the methine proton, and X the phosphorus atom) was carried out using the LAOCOON III computer program. The best set of parameters (rms error 0.061 Hz) obtained for the 60 MHz spectrum using 121 of the 128 calculated transitions is Δδ AB = 14.03 Hz, J AA, = 3.40, J BB, = −0.25, J AB = −8.12, J AB, = 0.35, J AX = 0.29, J BX = 3.83, J KX = 15.90, J AK = 3.34, and J BK = 0.16 Hz. The 100 MHz analysis produces nearly duplicate values. The exomethylene proton (A) is assigned the higher-field chemical shift. The 31P chemical shift is found to be anomalous considering previously observed trends in this parameter as a function of geometry.