6306-60-1Relevant articles and documents
Industrial preparation method of 2,4,5-trifluorophenylacetic acid
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Paragraph 0030; 0032; 0053, (2021/03/11)
The invention relates to the technical field of preparation of chemical drug intermediates, and particularly discloses an industrial preparation method of 2,4,5-trifluorophenylacetic acid. The preparation method comprises the following steps: carrying out a nitration reaction, a fluorination reaction, a hydrogenation reduction reaction, a diazotization reaction, a halogenation reaction, a cyaniding reaction, a thermal decomposition reaction and a hydrolysis reaction on 2,4-dichlorotoluene to prepare the 2,4,5-trifluorophenylacetic acid. The method has the advantages of low preparation cost andhigh product yield.
Nucleophilic Substitution of Aliphatic Fluorides via Pseudohalide Intermediates
Jaiswal, Amit K.,Prasad, Pragati K.,Young, Rowan D.
, p. 6290 - 6294 (2019/04/26)
A method for aliphatic fluoride functionalization with a variety of nucleophiles has been reported. Carbon–fluoride bond cleavage is thermodynamically driven by the use of silylated pseudohalides TMS-OMs or TMS-NTf2, resulting in the formation of TMS-F and a trapped aliphatic pseudohalide intermediate. The rate of fluoride/pseudohalide exchange and the stability of this intermediate are such that little rearrangement is observed for terminal fluoride positions in linear aliphatic fluorides. The ability to convert organofluoride positions into pseudohalide groups allows facile nucleophilic attack by a wide range of nucleophiles. The late introduction of the nucleophiles also allows for a wide range of functional-group tolerance in the coupling partners. Selective alkyl fluoride mesylation is observed in the presence of other alkyl halides, allowing for orthogonal synthetic strategies.
Crown ether functionalized magnetic hydroxyapatite as eco-friendly microvessel inorganic-organic hybrid nanocatalyst in nucleophilic substitution reactions: an approach to benzyl thiocyanate, cyanide, azide and acetate derivatives
Azaroon, Maedeh,Kiasat, Ali Reza
, (2017/10/09)
In this paper, high catalytic activity of 4′,4″-diformyl dibenzo-18-crown-6 anchored onto the functionalized magnetite hydroxyapatite (γ-Fe2O3@HAp–Crown) as a new, versatile and magnetically recoverable catalyst, was prepared. It evaluated as phase-transfer catalyst and molecular host system for nucleophilic substitution reactions of benzyl halides with thiocyanate, cyanide, azide and acetate anions in water. No evidence for the formation of by-products was observed and the products obtained in pure form without further purification. The nanocomposite was easily removed from solution via application of a magnetic field, allowing straightforward recovery and reuse. The synthesized nanocomposite was characterized by several techniques such as FT-IR, TGA-DTG, EDX, XRD, BET, FE-SEM, TEM and VSM.
Design and synthesis of a magnetic hierarchical porous organic polymer: A new platform in heterogeneous phase-transfer catalysis
Mouradzadegun, Arash,Ganjali, Mohammad Reza,Mostafavi, Mahsa Alsadat
, (2018/01/05)
Recyclable phase transfer catalysts containing magnetic nanoparticles (MNPs) have been known as a major trend towards sustainable catalysts. In this study, a novel class of magnetic porous polymer on the basis of calix[4]resorcinarene was synthesized starting from silica-coated Fe3O4 core-shell nanoparticles. This compound was found as an efficient phase transfer catalyst to the conversion of benzyl halides into benzyl azides and cyanides in good yields. The catalyst could be used at least for five consecutive cycles without appreciable loss in the catalytic activity.
Technological method for preparing halogenated-3,4-dihydro-1H-2-naphthalenone
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, (2017/07/20)
The invention relates to a technological preparation method of halogenated-3,4-dihydro-1H-2-naphthalenone as shown in a formula (I). (As shown in the description). According to the method disclosed by the invention, through a cheap raw material namely 2,4-dihalogeno-benzene carbonitrile, and an intermediate namely 2,4-dihalogeno-benzene acetic acid is synthesized, and through a reusable trifluoroacetic anhydride/acid system catalyst, a target product namely the halogenated-3,4-dihydro-1H-2-naphthalenone is synthesized. According to the method disclosed by the invention, a large quantity of catalysts such as aluminumtrichloride, and costly catalysts such as Rh, are not needed, and the reaction route can be shortened, so that a large quantity of reagents and time can be saved, and the industrial economic benefits can be greatly increased.
Preparation of novel magnetic dicationic ionic liquid polymeric phase transfer catalyst and their application in nucleophilic substitution reactions of benzyl halides in water
Godajdar, Bijan Mombani,Ansari, Bita
, p. 34 - 39 (2015/02/05)
PEG-based magnetic dicationic ionic liquid was successfully prepared and evaluated as phase-transfer catalyst for nucleophilic substitution reactions of benzyl halides for the synthesis of benzyl azides and cyanides from good to excellent yields at 90 °C in water. The reactions occur in water and furnish the corresponding benzyl derivatives in high yields. No evidence for the formation of by-product for example benzyl alcohol of the reaction was observed and the products were obtained in pure form without further purification.
Ionic liquid-induced conversion of methoxymethyl-protected alcohols into nitriles and iodides using [Hmim][NO3]
Noei, Jalil,Mirjafari, Arsalan
supporting information, p. 4424 - 4426 (2014/08/05)
This Letter reports a one-pot efficient conversion of methoxymethyl-ethers into their corresponding nitriles and iodides using the ionic liquid, 1-methyl-3H-imidazolium nitrate ([Hmim][NO3]) under microwave irradiation. A variety of products were prepared in high yields using this method.
Magnetic nanoparticles grafted with β-cyclodextrin-polyurethane polymer as a novel nanomagnetic polymer brush catalyst for nucleophilic substitution reactions of benzyl halides in water
Kiasat, Ali Reza,Nazari, Simin
, p. 80 - 86 (2013/01/14)
The polymer coated magnetic nanoparticles has gained significant attention for potential applications in biomedicine, separations, and magnetic storage. In this study, β-cyclodextrin-polyurethane polymer coated Fe 3O4 magnetic nanoparticle as a novel class of hybrid organic/inorganic molecular catalyst was successfully prepared and evaluated as solid-liquid phase-transfer catalyst and molecular host system for nucleophilic substitution reactions. The nanocomposite has demonstrated the ability to catalytic the nucleophilic substitution reaction of benzyl halides with thiocyanate, azide, cyanide and acetate anions in water. No evidence for the formation of by-products for example isothiocyanate or alcohol was observed and the products obtained in pure form without further purification. The nanomagnetic polymer brush catalyst was easily removed from solution via application of a magnetic field, allowing straightforward recovery and reuse. Results obtained from scanning electron microscopy (SEM) and vibrating sample magnetometery (VSM) show that the synthesized magnetic nanocomposite are superparamagnetic with a mean diameter of 59 nm. The grafting of β-cyclodextrin-polyurethane polymer to Fe3O4 magnetic nanoparticle is confirmed by Fourier transform infrared spectroscopy (FT-IR).
Application of β-cyclodextrin-polyurethane as a stationary microvessel and solid-liquid phase-transfer catalyst: Preparation of benzyl cyanides and azides in water
Kiasat, Ali Reza,Nazari, Simin
, p. 102 - 105 (2013/01/15)
Application of water tolerant heterogeneous catalyst, β-cyclodextrin- polyurethane (β-CDPU) polymer, as an efficient microvessel and polymeric host system for nucleophilic substitution reaction of benzyl halides with cyanide and azide anions in water has been described. The reactions gave only pure products, which did not require any further purification. The most important features of this method are high yields, clean reactions and that the catalyst can be recovered and recycled.