1226-23-9Relevant academic research and scientific papers
Deep eutectic solvent as an operative media on structure-reactivity relationships
Harifi-Mood, Ali Reza,Khorshahi, Hasan
, p. 511 - 519 (2019/04/14)
Deep eutectic solvents seem to be environmentally friendly solvents, particularly because they are prepared easily and have very low-vapor pressures under ambient conditions. They are suitable candidates as green solvents for reaction media with special properties. To present this behavior, substitution reactions of some para- and meta-substituted anilines with 1-fluoro-2,4-dinitrobenzene have been spectrophotometrically investigated in varying mole fractions of ethaline as a deep eutectic solvent in dimethyl sulfoxide (DMSO). The measured rate coefficients of the reaction demonstrated a noticeable variation with the increasing mole fraction of ethaline in ethaline-DMSO mixtures. The linear free energy relationship (LFER) of second-order rate coefficients based on Hammett's substituent constants demonstrates a reasonably linear straight line with a negative slope in different mole fractions of ethaline-DMSO mixtures. Another LFER investigation based on the polarity parameters of the media showed a good agreement with hydrogen bond donor and acceptor abilities of the solvent. Non-LFER assay according to the preferential solvation model confirmed differences between the microsphere solvation of the solute molecules and the bulk composition of the solvents.
“Zero VOC” Synthetic Strategy – Aromatic Amination Reactions in Deep Eutectic Solvents
Valvi, Arun,Tiwari, Shraeddha
, p. 4933 - 4939 (2018/09/11)
Rising concern for environment hazards resulting from the use of volatile organic compounds (VOCs) is prompting many chemists to use “green” solvents like water, polyethylene glycol, ionic liquids and deep eutectic solvents (DES). With a few notable exceptions, many of these processes still need to use volatile organic solvents for the workup and isolation of products. In the present report, we demonstrate a “zero VOC” protocol which eliminates the need to use organic solvents for any stage of the reaction. As a proof of concept, nucleophilic aromatic substitution reactions of 1-halo-2,4-dinitrobenzene with secondary amines were carried out in deep eutectic solvents. The reaction workup involved the addition of water for separating the product from the DES. Evaporation of water led to recovery of the DES, which exhibited good recyclability. The reaction in deep eutectic solvents was much faster than that in many other solvents, as confirmed by the kinetic studies. An attempt was made to elucidate the origin of this rate enhancement based on analysis activation parameters and correlation with the polarity parameters. The results show that use of deep eutectic solvents can take chemists a step closer towards the “zero VOC” synthetic strategy.
Reaction kinetics investigation of 1-fluoro-2,4-dinitrobenzene with substituted anilines in ethyl acetate-methanol mixtures using linear and nonlinear free energy relationships
Jamali-Paghaleh, Javad,Harifi-Mood, Ali Reza,Gholami, Mohammad Reza
experimental part, p. 1095 - 1100 (2012/02/15)
Aromatic nucleophilic substitution reaction of 1-fluoro-2,4-dinitrobenzene with para-substituted and meta-substituted anilines was kinetically investigated in the mixtures of ethyl acetate and methanol at room temperature. The correlation of second-order rate coefficients with Hammett's substituent constants yields a fairly linear straight line with negative slope in different mole fractions of ethyl acetate-methanol mixtures. The measured rate coefficients of the reaction demonstrated a dramatic variation in ethyl acetate-methanol mixtures with the increasing mole fraction of ethyl acetate. Linear free energy relationship (LFER) investigations confirm that polarity has a major effect on the reaction rate whereas the hydrogen-bonding ability of the media has a slight effect on it. Nonlinear free energy relationship based on preferential solvation hypothesis showed differences between the microsphere solvation of the solute and the bulk composition of the solvents, and non-ideal behavior is observed in the trend of the rate coefficients, which cover the LFER results. Copyright
REACTIONS BETWEEN 1-HALOGENO-2,4-DINITROBENZENES AND SUBSTITUTED ANILINES: KINETICS AND EVIDENCE FOR THE PRESENCE OF A MOLECULAR COMPLEX
Forlani, Luciano
, p. 205 - 212 (2007/10/02)
The title reactions (halogen = F or Cl) have been studied in benzene and in chloroform.The experimental reaction order in aniline is higher than 2 in every case (the value 3 is reached for the fluoro derivative in both solvents).Spectroscopic evidence (1H NMR and UV) indicates the presence of a molecular complex the formation of which (together with a base-catalysed step) is probably responsible for the observed kinetic features.The substituent effect (in aniline) is discussed.
