3871-20-3Relevant articles and documents
PHOSPHATE AND PHOSPHONATE BASED COMPOUNDS OF 6-THIO-2'-DEOXYGUANOSINE AS ANTI-CANCER AGENTS
-
Paragraph 00226, (2020/08/22)
Phosphates and phosphonates compounds of 6-thio-2'-deoxyguanosine are provided. The uses and pharmaceutical compositions of these compounds are disclosed.
Kinetics and adsorption calculations: insights into the MgO-catalyzed detoxification of simulants of organophosphorus biocides
Almerindo, Gizelle I.,Buratto, Suelen C.,Caramori, Giovanni F.,Fiedler, Haidi D.,Medeiros, Michelle,Micke, Gustavo A.,Nicolazi, Lucas M.,Nome, Faruk,Parreira, Renato L. T.,Sangaletti, Patrícia,Schneider, Felipe S. S.,Wanderlind, Eduardo H.
supporting information, p. 19011 - 19021 (2020/10/02)
We report the targeted decomposition of the organophosphate methyl paraoxon by means of its transesterification with 1-propanol catalyzed by magnesium oxide. Catalyst characterization by energy dispersive X-ray fluorescence (EDXRF), nitrogen adsorption/desorption measurements (BET and BJH methods), and temperature programmed desorption of CO2(CO2-TPD) showed that the employed MgO presents properties favorable for the methyl paraoxon adsorption and transesterification to occur. A thorough kinetic investigation showed that rate enhancements up to 3 × 106-fold can be achieved in comparison with the spontaneous propanolysis of the substrate, and that the material can be used in additional cycles without loss of catalytic activity, with the catalyst recovery achieved through a simple washing procedure. Energies for adsorption of 1-propanol and methyl paraoxon onto a MgO model surface were obtained by density functional theory calculations, which showed that the latter displays a stronger affinity for the catalyst surface, and that the reaction should proceed with methyl paraoxon and 1-propanol molecules juxtapositioned at adjacent Mg2+sites, with nucleophilic and electrophilic centersca.2.4 ? away from each other. Additionally, MgO also promoted rate enhancements up to 5 × 104-fold in the propanolysis of a further range of representative phosphate triesters, and in most of the cases the final transesterified products are trialkyl phosphates structurally related to a family of flame-retardants. The results thus provide insights into the development of novel systems for the targeted conversion of organophosphorus compounds into value-added products by employing simple, highly efficient, and low-cost metal oxide catalysts.
Novel flame-retarding and crosslinkable multifunctional compound for prepation of polyurethane, polyurea or hybrid polymer thereof
-
Paragraph 0103; 0105, (2019/08/14)
The present invention refers to novel flame retardant and crosslinkable a colored compound, for manufacturing method, and by using them flame-retardant high pressure liquid coolant and a thermosetting polyurethane or polyurea to number are disclosed. (by machine translation)
PROCESS FOR PREPARATION OF HIGHLY PURE DIALKYL PEMETREXED
-
Page/Page column 10, (2012/02/15)
The invention discloses a process for preparation of highly pure dialkyl pemetrexed by reacting a 2-(4-hydroxy-6-aminopyrrolo(2,3-d)pyrimidin-3-yl)ethylbenzoic acid with a glutamatic acid diester or its salt in presence of a safe, mild, inexpensive, non-oxidative and easy to handle reagent such as substituted triphenyl phosphate. The invention further discloses purification of dialkyl pemetrexed by crystallization or trituration and conversion of purified dialkyl pemetrexed to pemetrexed or its disodium salt.
Activating water: Important effects of non-leaving groups on the hydrolysis of phosphate triesters
Kirby, Anthony J.,Medeiros, Michelle,Oliveira, Pedro S. M.,Orth, Elisa S.,Brandao, Tiago A. S.,Wanderlind, Eduardo H.,Amer, Almahdi,Williams, Nicholas H.,Nome, Faruk
supporting information; experimental part, p. 14996 - 15004 (2012/02/03)
The high rate of spontaneous hydrolysis of tris-2-pyridyl phosphate (TPP) is explained by the activating effects of the non-leaving ("spectator" ) groups on P-OAr cleavage, and not by intramolecular catalysis. Previous work on phosphate-transfer reactions has concentrated on the contributions to reactivity of the nucleophile and the leaving group, but our results make clear that the effects of the non-leaving groups on phosphorus can be equally significant. Rate measurements for three series of phosphate triesters showed that sensitivities to the non-leaving groups are substantial for spontaneous hydrolysis reactions, although significantly smaller for reactions with good nucleophiles. There are clear differences between triaryl and dialkyl aryl triesters in sensitivities to leaving and non-leaving groups with the more reactive triaryl systems showing lower values for both βLG and βNLG. Intramolecular catalysis of the hydrolysis of TPP by the neighbouring pyridine nitrogens is insignificant, primarily because of their low basicity.
A Comparison between Kinetic Parameters from the Synthesis of Tris(p-nitrophenyl)phosphite and Tris(p-nitrophenyl)phosphate Using Reaction Calorimetry
Seiceira, Rafael C.,Machado E Silva, Carlos F. P.,Estevao, Luciana R. M.,Cajaiba Da Silva, Joao F.
, p. 954 - 956 (2013/09/05)
Tris(p-nitrophenyl)phosphite was prepared by a modification of a "one-pot" methodology developed for the preparation of triaryl phosphates. This exothermic reaction was performed in a Mettler RC-1 calorimeter. The principal aim of this work was to compare the reactivity of phosphorus trichloride and phosphorus oxychloride in their reactions with sodium p-nitrophenoxide. The reaction rate and the reaction rate constant for the synthesis of tris(p-nitrophenyl)phosphite were evaluated and compared to the obtained values for the tris(p-nitrophenyl)-phosphate synthesis. Phosphorus trichloride was found to react faster than phosphorus oxychloride, but the reaction with the phosphorus oxychloride proved to be more exothermic.
Evaluation of kinetic parameters from the synthesis of triaryl phosphates using reaction calorimetry
Machado e Silva, Carlos F. Pinto,Da Silva, Joao F. Cajaiba
, p. 829 - 832 (2013/09/06)
Triaryl phosphates were prepared by a "one-pot" methodology through the reaction of sodium phenoxides with phosphorus oxychloride. This system can be described as a semi-batch reaction, where the phenoxides were synthesized inside the reactor anda solution of phosphorus oxychloride in toluene was added continuously through a pump. These highly exothermic reactions were performed in a Mettler RC-1 reaction calorimeter. The aim of this work was to evaluate the reaction rate and the reaction rate constant through the study of the rate of heat release. Although the phenoxides react almost immediately with phosphorus oxychloride, it was possible to notice the slight differences among the sodium phenoxides studied. The phenoxide bearing an electron-donating group (methoxy) was the most reactive, and the one bearing an electron-withdrawing group (nitro) was the least reactive one. The reactions could be considered to be feed-controlled. It was demonstrated that the reaction temperature does not affect the reaction rate and reaction rate constant in the same way that the feed rate of the phosphorus oxychloride does.
"One-pot" Synthesis of Triaryl Phosphates a Reaction Calorimetry Approach
Silva, J. F. Cajaiba da,Nakayama, H. T.,Neto, C. Costa
, p. 71 - 82 (2007/10/03)
Triaryl phosphates were obtained in yields ranging from 85-96percent in a "one-pot" synthesis via an alkaline route: an ethanolic solution of sodium hydroxide was added to a solution of substituted phenol in toluene.The mixture was distilled until all ethanol was removed.Phosphorus oxychloride was then added and the toluene was distilled.The triaryl phosphates were characterized by NMR (1H and 31P), MS and FTIR.The heat capacity (Cp), the total heat transfer coefficient (U) and the reaction enthalpy (ΔH) were determined for the synthesis of tris(4-chloro-3-methylphenyl), tris(p-cresyl), tris(o-methoxyphenyl) and tris(p-nitrophenyl) phosphates. - Keywords: Phosphate; NMR spectra; heat capacity; phosphorus oxychloride
Electronic Structure and 31P NMR Chemical Shift of Substituted Triaryl, Diaryl Methyl and Dimethyl Aryl Phosphates - a Semi-empirical Molecular Orbital Approach
Silva, J. F. Cajaiba da,Pedrosa, M. S.,Nakayama, H. T.,Neto, C. Costa
, p. 97 - 106 (2007/10/03)
The 31P NMR chemical shift of triaryl phosphate, diaryl methyl phosphate and dimethyl aryl phosphate series was determined.The δ31P values exhibit an increasing downfield trend when aryl substituents are exchanged for alkyl groups and δ31P values show an increasing upfield trend as the electron withdrawing ability of the substituent in the aromatic ring is increased.Semi-empirical calculations showed an increasing positive charge on phosphorus atom and an increasing phosphoryl bond order when δ31P values go upfield.These results are in good agreement with the effect of "back bonding" from the phosphoryl oxygen to the phosphorus atom. - Keywords: 31P NMR chemical shifts; structural effects; molecular orbitals; triaryl phosphates; diaryl alkyl phosphates; dialkyl aryl phosphates
Phosphoryl-transfer reactions of phosphodiesters: Characterization of transition states by heavy-atom isotope effects
Hengge, Alvan C.,Cleland
, p. 5835 - 5841 (2007/10/02)
The secondary 18O and 15N isotope effects have been measured for phosphoryl-transfer reactions of the phosphodiester 3,3-dimethyl p-nitrophenyl phosphate under conditions of acid and alkaline hydrolysis, cleavage by β-cyclodextrin, and cleavage by snake venom phosphodiesterase. Isotopic labeling and other experiments show that these reactions proceed by an SN2(P) mechanism. The secondary 18O isotope effect measures changes in transition state bonding to the nonbridge oxygen atoms in the central phosphoryl group in these SN2 reactions. The 15N isotope effects measure transition-state bond cleavage to the leaving group p-nitrophenol. The isotope effect data indicate that weaker nucleophiles lead to a more associative transition state with respect to the central phosphoryl group (decreased bonding to the nonbridge oxygens) while the extent of bond cleavage to the leaving group is affected little. Comparison of isotope effect data from the attack of hydroxide on a phosphodiester monoanion with that of a neutral phosphotriester suggests the oxyanion in the diester may assist in expulsion of the leaving group.
