Diethyl Methylphosphonate Research Articles

Phase Behavior of Diethyl Methylphosphonate and 2-Chloroethyl Methyl Sulfide in Supercritical Carbon Dioxide

Pressure−composition isotherms are reported for diethyl methylphosphonate and 2-chloroethyl methyl sulfide in carbon dioxide at 35, 55, and 75 °C. These two CO2−polar solute systems do not exhibit three-phase equilibria in the vicinity of the critical point of CO2. Pressures less than ≈140 bar are needed to obtain a single phase for both binary mixtures at temperatures up to 75 °C.

A SIMPLE AND EFFICIENT PREPARATION OF (ARYLPHOSPHINYL)-METHYLPHOSPHONATES

ABSTRACT A simple and efficient preparation of (arylphosphinyl)methylphosphonates is described whereby the phosphinylmethylphosphonate group is introduced via the Pd(0) mediated phosphinylation of an aryl halide or triflate with diethyl (ethoxyphosphinyl)methylphosphonate.

Synthesis of Diethyl (2-acetyl-5-methyl-3-oxo-1,2,3λ5-Δ5-diazaphospholin-3-yl)methylphosphonate

Synthesis of Diethyl (2-acetyl-5-methyl-3-oxo-1,2,3λ5-Δ5-diazaphospholin-3-yl)methylphosphonate

Reactions of Hydroxyl Radical with Dimethyl Methylphosphonate and Diethyl Methylphosphonate. A Fundamental Mechanistic Study

Dimethyl methylphosphonate (DMMP) and diethyl methylphosphonate (DEMP) were used as models for hazardous organophosphorus compounds to study their radiolytic reactions. Hydrated electrons and super...

Multivariate Curve Resolution of Wavelet and Fourier Compressed Spectra

The multivariate curve resolution method SIMPLe to use Interactive Self-Modeling Mixture Analysis (SIMPLISMA) was applied to Fourier and wavelet compressed ion-mobility spectra. The spectra obtained from the SIMPLISMA model were transformed back to their original representation, that is, uncompressed format. SIMPULSMA was able to model the same pure variables for the partial wavelet transform, although for the Fourier and complete wavelet transforms, satisfactory pure variables and models were not obtained. Data were acquired from two samples and two different ion mobility spectrometry (IMS) sensors. The first sample was thermally desorbed sodium gamma-hydroxybutyrate (GHB), and the second sample was a liquid mixture of dicyclohexylamine (DCHA) and diethylmethylphosphonate (DEMP). The spectra were compressed to 6.3% of their original size. SIMPLISMA was applied to the compressed data in the Fourier and wavelet domains. An alternative method of normalizing SIMPLISMA spectra was devised that removes variation in scale between SIMPLISMA results obtained from uncompressed and compressed data. SIMPLISMA was able to accurately extract the spectral features and concentration profiles directly from daublet compressed IMS data at a compression ratio of 93.7% with root-mean-square errors of reconstruction < 3%. The daublet wavelet filters were selected, because they worked well when compared to coiflet and symmlet. The effects of the daublet filter width and compression ratio were evaluated with respect to reconstruction errors of the data sets and SIMPLISMA spectra. For these experiments, the daublet 14 filter performed well for the two data sets.

Iodine atom transfer addition reaction of 1-iodoalkyl phosphonates to alkenes in the presence of α,α′-azoisobutyronitrile (AIBN): mechanistic aspects

The objectives of this work were to elucidate the mechanistic pathway of the title reaction, which constitutes the first example of a radical iodine atom transfer addition reaction of non-fluorine-containing phosphonates, and to determine whether 2-iodo-2-methylpropionitrile, 8, can serve as a competing iodine donor with the starting diethyl 1-iodoalkyl phosphonates, 1a,b. The title reaction was found to proceed with AIBN as the sole radical initiator, not requiring poisonous tin reagents as co-initiators, and gave diethyl 3-iodoalkylphosphonates 3a–e (the final products of the propagation step, isolated in 59–95% yield), tetramethylsuccinodinitrile, 9, diethyl methylphosphonate, 4 and tetraethyl ethylenebisphosphonate 5 (all termination products, 0–10% yields). The radical character of this reaction was demonstrated using TEMPO as a radical trap. 8 (the intermediate of the initiation step), synthesized independently from AIBN and iodine, caused complete inhibition of the reaction when added to the reaction mixture, indicating that it does not behave as an iodine donor in the transfer stage, but rather as an inhibitor.

The by-products generated during sarin synthesis in the Tokyo sarin disaster induced inhibition of natural killer and cytotoxic T lymphocyte activity

More than 5000 passengers on Tokyo subway trains were injured by the nerve gas, sarin and its by-products. Analysis of phosphor-carrying metabolites of sarin and its by-products in urine samples from the victims suggested that they were exposed not only to sarin, but also by-products generated during sarin synthesis, i.e. diisopropyl methylphosphonate (DIMP) and diethyl methylphosphonate (DEMP). We suspected genetic after-effects due to sarin by-products, thus, we checked the frequency of sister chromatid exchange (SCE) and found that SCE was significantly higher in the victims than in a control group, and that DIMP and DEMP significantly induced human lymphocyte SCE in vitro. In the present study, to explore whether DIMP and DEMP, which induced a high frequency of SCE of lymphocytes, also affected the lymphocyte functions, we examined the effect of DIMP and DEMP on splenic natural killer (NK) and splenic cytotoxic T lymphocyte (CTL) activity in mice, and NK activity of human lymphocytes in vitro. We found that DIMP and DEMP significantly inhibited NK and CTL activity in a dose-dependent manner. The inhibition induced by DIMP was stronger than that by DEMP. The effect of DIMP and DEMP on the splenic NK activity of mice was stronger than on the splenic CTL activity, and the human lymphocytes is more sensitive to DIMP and DEMP than the splenocytes of mice.

New perspectives on the cardioprotective phosphonate effect of the spin trap 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline N-oxide: an hemodynamic and 31P NMR study in rat hearts

The spin trap 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline N-oxide (DEPMPO) is an improved ESR probe to assess superoxide (O 2 •−) formation in the postischemic heart. We recently found that DEPMPO pretreatment improves recovery of cardiac function with the concomitant inhibition of postischemic O 2 •− production. By perfusing diethyl methylphosphonate MeP(O)(OEt) 2 to ischemic-reperfused isolated rat hearts, we provide hemodynamic evidence that this preservation, which exerts during ischemia, is in fact specific to the phosphonate group. Using 31P NMR on intact rat hearts, it was also found that the “phosphonate effect” of DEPMPO is related to the preservation of ATP levels during ischemia, when compared to 5,5-dimethyl-1-pyrroline N-oxide. This mechanism may be a means of reducing the potency of cardiac tissue to produce O 2 •− during reperfusion.

The permeation of organophosphorus compounds in silicone rubber membranes

The permeabilities, solubilities, and diffusivities of eight organophosphorus chemicals in silicone rubber were measured at saturation concentration using two different experimental methods: permeation experiments and absorption experiments. All tests were carried out at 25°C (±3°C). The eight organophosphorus chemicals investigated are dimethyl methylphosphonate, diethyl methylphosphonate, dimethyl hydrogenphosphonate, diethyl hydrogenphosphonate, trimethylphosphate, triethylphosphate, trimethylphosphite, and triethylphosphite. These eight chemicals were selected based on their similarities to organophosphorus chemicals used as pesticides and chemical warfare agents. The experimental data were analyzed using solutions of Fick's second law of diffusion and boundary conditions representative of the experimental settings. An unsteady-state diffusion model using boundary conditions that represent uniform initial concentration in the polymer and constant but different surface concentrations was used to interpret the permeation experimental data. In this model, the effective diffusivity calculated from the steady-state permeability and equilibrium solubility of each chemical was used and was assumed to be constant.

Elevated frequency of sister chromatid exchanges in lymphocytes of victims of the Tokyo sarin disaster and in experiments exposing lymphocytes to by-products of sarin synthesis

More than 5000 passengers of Tokyo subway trains were injured with toxic chemicals including the nerve gas sarin. Most of the victims examined had marked miosis and decreased serum cholinesterase activity. To monitor the genetic aftereffects of sarin exposure, we measured sister chromatid exchanges (SCEs) of the victims using peripheral blood lymphocytes. The frequency of SCEs was significantly higher in the victims than in the control group. Analyzing results using samples of urine from the victims suggested that the victims were exposed to not only sarin per se, but by-products of sarin synthesis, i.e. diisopropyl methylphosphonate (DIMP), diethyl methylphosphonate (DEMP) and ethyl isopropyl methylphosphonate (EIMP). Thus, the in vitro SCE-inducing effect of DIMP, DEMP and EIMP was examined using human lymphocytes and we obtained positive results.

Biological monitoring of metabolites of sarin and its by-products in human urine samples.

More than 20,000 passengers of Tokyo underground trains were intoxicated with warfare toxic chemicals. Most of the patients examined had marked miosis and decreased serum cholinesterase activity. Transient increase of serum CPK activity after 3 days of the exposure was the another sign. We intensively analyzed the metabolites in the urine of 4 patients. The following analytic results indicated the exposure to sarin as well as contaminated compounds such as diisopropyl methylphosphonate (DIMP), ethyl methylphosphonate fluoridate (EMPF, or ethylsarin), diethyl methylphosphonate (DEMP), and ethyl isopropyl methylphosphonate (EIMP). (1) Isopropanol (IPA) and ethanol (EtOH) were detected of large quantities in the urine samples, and were thought to be derived from sarin and the sarin counterpart, EMPF, DIMP, DEMP and EIMP. (2) Monoalkyl methylphosphonic acids (isopropyl methylphosphonic acid (IMPA) and ethyl methylphosphonic acid (EMPA) also were excreted in large amounts with taking the similar excretion pattern of IPA and EtOH. (3) The metabolite only derived from sarin and ethylsarin is F anions whose integral output in the urine was less than the equimolar level of the excreted (IMPA + EMPA + IPA + EtOH). (4) Other corroborative findings were low lethality: of more than 5,510 patients treated, 11 were acutely dead. (5) Nine exposed males had higher sister chromatid exchange (SCE) rate (5.00 +/- 1.48/cell) than the control (3.81 +/- 0.697/cell), because dialkyl methylphosphonates seemed to have alkylating activity and producing DNA adducts. The SCE rate also increased after the in vitro exposure of lymphocytes to dialkyl methylphosphonates.

Photocatalytic decomposition of organophosphonates in irradiated TiO 2 suspensions

Kinetic analyses of the TiO 2-catalyzed photodegradation of dimethyl methylphosphonate (DMMP) and diethyl methylphosphonate (DEMP) in oxygenated aqueous solutions are described. The effects of substrate concentration and solution pH are investigated. A number of kinetic models appear to be applicable in accordance with the initial kinetic parameters. The major products formed from the photocatalytic decomposition of DMMP are methylphosphonic acid, phosphoric acid, formaldehyde and formic acid.

TiO2 photocatalytic degradation of dimethyl- and diethyl- methylphosphonate, effects of catalyst and environmental factors

Dimethyl methylphosphonate (DMMP) and diethyl methylphosphonate (DEMP) are readily mineralized by photoexcited titanium dioxide (TiO2). Intermediate products include low molecular weight organic acids and methylphosphonic acid. Complete mineralization yields phosphate and carbon dioxide. The photoactivities of different types of TiO2 were investigated. The decomposition kinetics of DMMP and effects of DMMP and catalyst concentration, sonication, solar irradiation, oxygen concentration, temperature, and hydrogen peroxide on the rate of decomposition are reported. The degradation rates increase with simultaneous sonication, addition of hydrogen peroxide, and at higher temperatures.

A Convenient (E)-Stereoselective Synthesis of Alkenylphosphonates

Diethyl (E)-alkenylphosphonates have been prepared stereoselectively by dehydration of the corresponding β-hydroxyphosphonates using DCC/CuCl2 in refluxing toluene. Starting β-hydroxyphosphonates were obtained in high yield from diethyl methylphosphonate.

Gas-Phase Pyrolysis of Diethyl Methylphosphonate

Flow reactor pyrolysis studies of diethyl methylphosphonate (DEMP) in nitrogen have been conducted over the temperature range 802 to 907 K, to gain insight into decomposition mechanisms relevant to incineration of organophosphorus chemical warfare agents. Experiments were conducted in a quartz-lined turbulent flow reactor with residence times between J5 and 125 ms. Two techniques are used to identify products: Fourier-transform infrared (FTIR) spectroscopy for volatile compounds, and gas chromatography/mass spectrometry (GC/MS) preceded by derivatization for products trapped in a liquid-nitrogen bath. Ethylene, ethanol, ethyl methylphosphonate, and methylphosphonic acid were identified as products; ethylene, ethanol and DEMP were quantified using FTIR. The mean ratio of ethylene to ethanol is 1.66. Rates of DEM P decomposition and product formation are independent of loading and reactor diameter. The temperature dependence of the overall DEMP decomposition rate constant was found to be: k[s-'] = 2.9 X 10'...

Synthesis of 4,5-Dihydroisoxazoles Bearing Phosphonate Moiety

Abstract Introduction of phosphoryl group usually leads to the improvement of biological activity of the parent molecule. A facile synthetic route was introduced based on an intramolecular silylnitronate-olefin cyclo-addition (ISOC) reaction. Thus, 3-(β-diethoxyphosphoryl)-ethyl-5-methoxycarbonyl - 4,5 -dihydroisoxazole (1), 3-(α-diethoxyphosphoryl- α -substituted methyl) - 5 - methoxycarbonyl - 4,5 - dihydroisoxazole (2) and 3 - methyl - 4 -alkyl(aryl) - 5 - bisphosphoryl - 4,5 - dihydroisoxazole (3) were prepared from diethyl methylphosphonate, diethylphosphite and methylene bisphosphonate respectively after treatment with BuLi or LDA and appropriate nitroalkene followed by ClSiMe3. Condensation of but - 3 - en - 1 - yl phosphonate with nitroalkene, followed by ClSiMe3, led to the stereoselective synthesis of fused carboisoxazole derivatives (4). In the case of aryl substituted α- nitroalkene, the reaction undergoes stereoselectively due to the formation of transition state of the least steric hindrance...

A Facile Preparation of 2-Arylethenephosphonates

Abstract Vinylphosphonates 3 could be prepared with E-selectivity by the condensation of diethyl methylphosphonate 1 with a series of carbonyl compounds using diethyl chlorophosphate.

ChemInform Abstract: Phosphonic Systems. Part 9. Solution and Solid State Structure of R,R ( S,S) Stereoisomers of the Adducts of Diethyl(1‐cyclohexenyl) methylphosphonate and Aldehydes

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Phosphonic systems Part 9. Solution and solid state structure of R,R (S,S) stereoisomers of the adducts of diethyl(1-cyclohexenyl)methylphosphonate and aldehydes

Abstract The solution and solid state structures of single stereoisomers of α-adducts of diethyl(1-cyclohexenyl)methyl-phosphonate and three aldehydes were determined by NMR spectroscopy and by X-ray diffraction. In both phases, the molecules exist in virtually the same conformation, involving gauche orientation of the PO 3 Et 2 and the 2-hydroxy groups, and trans orientation of the former group and the R group of the aldehyde molecule. In the crystal, this conformation is retained in spite of the fact that PO⋯HO hydrogen bonding occurs inter- and not intramolecularly.

Expedient Synthesis of 1,1-Diiodoalkenes

1,1-Diiodoalkenes 1 were readily prepared from carbonyl compounds 2 and diethyl diiodomethylphosphonate (3), generated in situ from commercial diethyl iodomethylphosphonate (4) or diethyl methylphosphonate (5). Starting from aldehydes, iodoacetylenes 6 could be obtained directly in situ by dehydrohalogenation of diiodoalkenes 1