34063-52-0Relevant academic research and scientific papers
Scalable, easy synthesis, and efficient isolation of arylnitromethanes: a revival of the Victor Meyer reaction
Alaime, Thibaud,Delots, Audrey,Pasquinet, Eric,Suzenet, Franck,Guillaumet, Gérald
, p. 1337 - 1341 (2017/01/21)
A modified approach to synthesize and isolate arylnitromethanes is described. The method takes advantage of the significant difference in acidity between the arylnitromethane and the major impurity of the reaction, the nitrite ester. The arylnitromethanes resulting from this process are obtained in high yields and are analytically pure, i.e., they do not require distillation or further purification, which is a comfortable improvement of the ancestral Victor Meyer reaction.
Reactions of substituted phenylnitromethane carbanions with aromatic nitro compounds in methanol: Carbanion reactivity, kinetic, and equilibrium studies
Asghar, Basim H.
, p. 477 - 488 (2014/07/08)
The feasibility of carrying out nucleophilic addition from electron-deficient heteroaromatics has been addressed through a detailed investigation of the interaction of a two 7-substituted-nitrobenzofurazan (R = OMe 2a; R = Cl 2b) with a series of substituted-nitroaryl anions (X = 4-NO 2 1a; X = 3-NO2 1b; X = 4-CN 1c; X = 4-Br 1d), all reactions first lead to the quantitative formation of the σ-adducts 3a-d and 4a-d arising from covalent addition of the nucleophile to the C-5 carbon. The rate and equilibrium constants for the formation of σ-adducts 3a-d and 4a-d (k5, K5) together with the rate constants for their decomposition (k-5) have been determined in methanol at 25C, allowing a determination of intrinsic rate constants, k0 = 0.03, the lower k0 value reflects the very strong salvation by methanol of the negative charge on the nitro group. The discovery of a linear correlation between the E and pKaMeOH parameters allows a calibration of the electrophilicity power of 2a and 2b, E = -11.67 and -10.29, respectively. Applying the general approach to nucleophilicity/electrophilicity recently developed by Mayr et al. through the relationship log k = s(E + N), a successful ranking of our nitroaryl anions 1a-d on the general nucleophilicity scale (N) has been carried out. The N values of 1a-d are found to cover a range from 15.78 to 16.69. The results are compared with previously reported data in water and DMSO.
Synthesis of unsymmetrical 3,4-diaryl-3-pyrrolin-2-ones utilizing pyrrole weinreb amides
Greger, Jessica G.,Yoon-Miller, Sarah J. P.,Bechtold, Nathan R.,Flewelling, Scott A.,MacDonald, Jacob P.,Downey, Catherine R.,Cohen, Eric A.,Pelkey, Erin T.
, p. 8203 - 8214 (2011/12/04)
A regiocontrolled synthesis of unsymmetrical 3,4-diaryl-3-pyrrolin-2-ones has been achieved in three steps from 1,2-diaryl-1-nitroethenes with pyrrole-2-carboxamides (pyrrole Weinreb amides) serving as the key linchpin intermediates. Two different methods for the preparation of the requisite nitroalkenes were investigated: (1) modified Henry reaction between arylnitromethanes and arylimines; and (2) Suzuki-Miyaura cross-coupling reaction of 2-aryl-1-bromo-1-nitroethenes with arylboronic acids. Some difficulty was encountered in the preparation of arylnitromethanes, thus leading to the exploration of a cross-coupling strategy that proved more useful. A Barton-Zard pyrrole cyclocondensation reaction between 1,2-diaryl-1-nitroethenes and N-methoxy-N-methyl-2-isocyanoacetamide gave the corresponding pyrrole Weinreb amides, which were then converted into the desired 3-pyrrolin-2-ones in two steps. Overall, this method allowed for the construction of 3,4-diaryl-3- pyrrolin-2-ones with complete regiocontrol of the substituents with respect to the lactam carbonyl. The utility of this synthetic methodology was demonstrated by the preparation of eight unsymmetrical and symmetrical 3,4-diaryl-3-pyrrolin- 2-ones including the N-H lactam analogue of the selective COX-II inhibitor, rofecoxib.
Kinetic study of proton-transfer reactions of phenylnitromethanes. Implication for the origin of nitroalkane anomaly
Ando, Kenichi,Shimazu, Yu,Seki, Natsuko,Yamataka, Hiroshi
experimental part, p. 3937 - 3945 (2011/07/08)
Measurements of rate constants and substituent effects for three important elementary steps of proton-transfer reactions of phenylnitromethane were reported. The Hammett ? values for the deprotonation of ArCH2NO 2 with OH-
Nucleophilicities of nitroalkyl anions
Bug, Thorsten,Lemek, Tadeusz,Mayr, Herbert
, p. 7565 - 7576 (2007/10/03)
The kinetics of the reactions of eight nitroalkyl anions (nitronate anions) with benzhydrylium ions and quinone methides in DMSO and water were investigated photometrically. The second-order rate constants were found to follow a Ritchie constant selectivi
Proton transfer from carbon acids to carbanions. 1. Reactions of various carbon acids with the anions of substituted benzylmalononitriles in 90% Me2SO-10% water. determination of intrinsic barriers of identity reactions from the marcus relationship
Bernasconi, Claude F.,Ni, Jiu Xiang
, p. 5060 - 5066 (2007/10/02)
A kinetic study of the reversible deprotonation of 9-cyanofluorene (2), 1,3-indandione (3), 4-nitrophenyl-acetonitrile (4), (3-nitrophenyl)nitromethane (5), and (4-nitrophenyl)nitromethane (6) by the anions of substituted benzylmalononitrile (1-X-) in 90% Me2SO-10% water (v/v) at 20 °C is reported. Intrinsic rate constants and intrinsic barriers of these reactions have been determined by extrapolation or interpolation of Br?nsted plots whose slopes (β) are all close to 0.5. Intrinsic barriers of the identity reactions CH + C- ? C- + CH (CH = 2,3,4,and phenylnitromethane) have been estimated on the basis of the Marcus equation, coupled with either a plausible value for the identity barrier of the reaction AH+ + A ? A + AH+ (A = piperidine or morpholine) ("amine method") or a plausible value for the identity barrier of the reaction 2 + 2- ? 2- + 2 ("9-cyanofluorene method"). There are discrepancies in the identity barriers for CH + C- ? C- + CH (CH = 2, 3, 4, and phenylnitromethane) calculated by the two methods. Possible reasons for these discrepancies and the significance of the results in terms of the validity and scope of the Marcus equation are discussed.
Kinetics of deprotonation of arylnitromethanes by benzoate ions in acetonitrile solution. Effect of equilibrium and nonequilibrium transition-state solvation on intrinsic rate constants of proton transfers
Gandler, Joseph R.,Bernasconi, Claude F.
, p. 631 - 637 (2007/10/02)
Second-order rate constants for benzoate ion promoted deprotonation reactions of (3-nitropbenyl)nitromethane, (4-nitrophenyl)nitromethane, and (3,5-dinitrophenyl)nitromethane have been determined in acetonitrile solution at 25 °C. These data were obtained at low benzoate buffer concentrations (a= 21.7; (4-nitromethyl)nitromethane, pKa = 20.6; and (3,5-dinitrophenyl)nitromethane, pKa, = 19.8. A Br?nsted βB value of 0.56 and an αCHlue of 0.79 have been calculated for the benzoate, 3-bromobenzoate, and 4-nitrobenzoate ion promoted reactions of (3,5- dinitrophenyl)nitromethane and for the benzoate ion promoted reactions of (3- nitrophenyl)nitromethane and (3,5-dinitrophenyl)nitromethane, respectively; (4-nitrophenyl)nitromethane deviates negatively from the Bronsted plot due to the resonance effect of the 4-nitro group. The logarithms of the intrinsic rate constants for benzoate promoted deprotonations of (3-nitrophenyl)nitromethane, (4-nitro phenyl)nitromethane, and (3,5-dinitrophenyl)nitromethane are 4.81, 4.58, and 5.27, respectively, and these values are 1.43, 1.70, and 1.30 log units, respectively, higher in acetonitrile than in dimethyl sulfoxide. Transfer activity coefficients from dimethyl sulfoxide (D) to acetonitrile (A) solution, log DγA, for (3-nitropbenyl)nitroimethyl anion (0.28), (4-nitrophenyl)nitromethyl anion (0.56), (3-nitrophenyl)nitromethane (0.18), and (4-nitrophenyl)nitromethane (0.16) have been calculated, and log DγA for benzoic acid (～ 1.9) and the benzoate ion (～0.25) have been estimated. The solvent effects on the intrinsic rate constants are analyzed within the framework of the Principle of Nonperfect Synchronization (PNS) in terms of contributions by late solvation of the arylnitromethyl anion, late solvation of the benzoic acid (produced as a product of the reaction), early desolvation of the benzoate ion and the arylnitromethane, and by a classical solvent effect. The results are also compared with predictions by a theoretical model recently proposed by Kurz. For the comparison of intrinsic rate constants in water and dimethyl sulfoxide there is good agreement between the Kurz model and the experimental results as well as the PNS analysts, but there is a discrepancy between the results and the predictions of the Kurz model for the comparison of intrinsic rate constants in dimethyl sulfoxide and acetonitrile solutions.
