85166-94-5Relevant academic research and scientific papers
Stereoselective synthesis and biological activities of diethyl (E)-{[4-cyano-5-[[(disubstitutedamino)methylene]amino]-3-(methylthio) -1H-pyrazol-1-yl]substituited phenylmethyl}phosphonates
Xiao, Lin-Xia,Shi, De-Qing
experimental part, p. 555 - 559 (2009/09/06)
(Chemical Equation Presented) Diethyl {[5-amino-4-cyano-3-(methylthio)-1H- pyrazol-1-yl]substitutedphenylmethyl}phosphonates 3 were efficiently synthesized via the condensation of [(1-hydrazino)substitutedphenylmethyl]phosphonates 1 with 2-[bis(methylthio
An α-hydrazinoalkylphosphonate as building block for novel N-phosphonoalkylheterocycles
Li, Zai-Guo,Sun, Hui-Kai,Wang, Qing-Min,Huang, Run-Qiu
, p. 384 - 386 (2007/10/03)
α-Hydrazinoalkylphosphonate 3 is a useful building block for the syntheses of novel N-phosphonoalkylheterocycles. N-phosphonoalkylpyrazoles 8 and 9 were prepared by the cyclization reaction of 3 with malfunctioned ethenes 5 and 6 in ethanol under reflux. N-Phosphonoalkyltriazole 10 was synthesized from 3 with N-dimethylthiomethylene benzoyl amide 4 in ethanol under reflux. The structures were confirmed by IR, 1H NMR, mass spectroscopy, and elemental analysis. At the same time, the preparation of 4 was investigated.
Studies of organophosphorus compounds 91: A novel synthesis of 1-hydrazinoalkylphosphonic acids and derivatives thereof
Yuan,Li
, p. 507 - 510 (2007/10/03)
Condensation of diethyl phosphite with aldehydes followed by subsequent sulfonylation of the resulting hydroxy group formed with mesyl chloride gave the corresponding 1-sulfonyloxyalkylphosphonates, which led to the convenient synthesis of 1-hydrazinoalky
Stabilization Demands of Diethyl Phosphonate Substituted Carbocations as Revealed by Substituent Effects
Creary, Xavier,Underiner, Ted L.
, p. 2165 - 2170 (2007/10/02)
Trifluoroethanolyses of a series of mesylate derivatives of diethyl (1-aryl-1-hydroxymethyl)phosphonates, 9, gave a Hammett ρ value of -10.1 in the electron donor substituent region.This value was slightly less than the value of -11.6 seen in the corresponding benzyl mesylates, ArCH2OMs, 12, in hexafluoroisopropyl alcohol.These data suggest that the demand for aryl group stabilization in the intermediate phosphoryl-substituted cation 10 does not surpass that of the α-H analogues, the benzyl cations.Some other factor must therefore account for the relative ease of formation of cations 10, which have the electronegative diethyl phosphonate group attached directly to the cationic center.The likely factor is an offsetting cation stabilizing feature associated with the diethyl phosphonate group.The Hammett plots for both mesylates 9 and 12 show a break, with decreased ρ values (-6.1 and -5.1, respectively) being observed in the electron-withdrawing region of the plot.Solvent effect studies on 9-m-F suggested that a change to "borderline behavior" is the origin of the break in the Hammett plot.A mechanistic change to the kδ process could be ruled out.The triflate derivative of diethyl (1-hydroxyethyl)phosphonate, 14, gave mixtures of substitution and elimination products on solvolysis.Solvent effect studies indicated a largely nucleophilic mechanism, while isotope effect studies were in line with some cationic character in the transition state in the highly ionizing, nonnucleophilic hexafluoroisopropyl alcohol solvent.Ion pair formation or the SN2 (intermediate) mechanism could rationalize the behavior of 14 in more highly ionizing solvents.
Mesylate Derivatives of α-Hydroxy Phosphonates. Formation of Carbocations Adjacent to the Diethyl Phosphonate Group
Creary, Xavier,Geiger, Cristina C.,Hilton, Kathryn
, p. 2851 - 2858 (2007/10/02)
Mesylates 3-6 have been prepared and reacted in a variety of solvents.Product, rate, and solvent effect studies implicate carbocationic intermediates in these solvolyses despite the electron-withdrawing PO(OEt)2 group.Mesylate 3 gave exclusive substitution products.Optically active 3 gave racemic products on trifluoroacetolysis. α-Deuterium isotope effects were also in line with a cationic intermediate.Mesylate 4 gave some elimination product, 27, along with the substitution product 28, also via a cationic intermediate.Mesylates 5 and 6 gave exclusive elimination products.A β-deuterium isotope effect study gave a kH6/kD6 value of 2.8.This isotope effect, along with a small m value (0.45), suggested the intermediacy of a reversibly formed ion pair which subsequently loses a proton.This mechanism represents the merging of the classical E1 mechanism and the E2C(+) mechanism, the latter representing the cationic counterpart of the E1cb mechanism.Analysis of the solvolysis rates of 3 and 4 led to the conclusion that cationic intermediates are formed quite easily.Reasons are suggested for this unexpectedly facile generation of cations adjacent to the potent electron-withdrawing PO(OEt)2 substituent.
