618-62-2Relevant articles and documents
Production process of 3,5-dichloronitrobenzene
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Paragraph 0028-0052, (2021/03/18)
The invention provides a production process of 3,5- dichloronitrobenzene, and belongs to the field of preparation of pesticide intermediates. The method comprises the following steps: adding nitrosylsulfuric acid with the mass fraction of 42% into a reaction kettle, conducting cooling to 5 DEG C, sequentially adding 2,6-dichloro-4-nitroaniline or 4,6-dichloro-o-nitroaniline, isopropanol and desalted water to respectively complete diazotization, denitrification and hydrolysis processes, wherein the temperature of the whole process is not higher than 45 DEG C; conducting steam extraction with water vapor at 100 DEG C to recover isopropanol and acetone, separating diluted sulfuric acid and 3,5-dichloronitrobenzene from a reaction solution after steam extraction, washing 3,5-dichloronitrobenzene with water, carrying out hydrogenation reduction on the washed 3,5-dichloronitrobenzene to produce 3,5-dichloroaniline, carrying out vacuum concentration and high-temperature concentration on thediluted sulfuric acid to obtain 97% concentrated sulfuric acid to prepare nitrosyl sulfuric acid, and separating a sulfuric acid concentrated distillate through an R/O membrane to prepare desalted water, and recycling the desalted water in the process. The process provided by the invention has the advantages of high yield, no pollution and low cost, and is a green production process.
meta-Nitration of Arenes Bearing ortho/para Directing Group(s) Using C?H Borylation
Li, Xuejing,Deng, Xingwang,Coyne, Anthony G.,Srinivasan, Rajavel
supporting information, p. 8018 - 8023 (2019/05/29)
Herein, we report the meta-nitration of arenes bearing ortho/para directing group(s) using the iridium-catalyzed C?H borylation reaction followed by a newly developed copper(II)-catalyzed transformation of the crude aryl pinacol boronate esters into the corresponding nitroarenes in a one-pot fashion. This protocol allows the synthesis of meta-nitrated arenes that are tedious to prepare or require multistep synthesis using the existing methods. The reaction tolerates a wide array of ortho/para-directing groups, such as ?F, ?Cl, ?Br, ?CH3, ?Et, ?iPr ?OCH3, and ?OCF3. It also provides regioselective access to the nitro derivatives of π-electron-deficient heterocycles, such as pyridine and quinoline derivatives. The application of this method is demonstrated in the late-stage modification of complex molecules and also in the gram-scale preparation of an intermediate en route to the FDA-approved drug Nilotinib. Finally, we have shown that the nitro product obtained by this strategy can also be directly converted to the aniline or hindered amine through Baran's amination protocol.
Dimethyl sulfoxide-accelerated reductive deamination of aromatic amines with t-BuONO in tetrahydrofuran
Fang, Lu,Qi, Liang,Ye, Longfei,Pan, Zhentao,Luo, Wenjun,Ling, Fei,Zhong, Weihui
, p. 579 - 583 (2018/11/27)
An efficient method for the conversion of aryl amines into arenes by a one-pot reductive deamination has been achieved. It was found the reductive deamination using t-BuONO in tetrahydrofuran could be accelerated by dimethyl sulfoxide and provided the deamination products with good yields under mild conditions. A plausible mechanism is discussed.
1-Aryl-3,3-dialkyltriazenes: A convenient synthesis from dry arenediazonium o-benzenedisulfonimides - A high yield break down to the starting dry salts and efficient conversions to aryl iodides, bromides and chlorides
Barbero,Degani,Diulgheroff,Dughera,Fochi
, p. 2180 - 2190 (2007/10/03)
This research comprises three parts. The first part regards the synthesis of 1-aryl-3,3-dialkyltriazenes 3 by reaction of dry arenediazonium o-benzenedisulfonimides 1, also coming from weakly basic aromatic amines with dimethylamine or diethylamine in aqueous solution at 0-5 °C. Yields were usually greater than 90% and there was the possibility of recovering the o-benzenedisulfonimide (5), which could be reused to prepare the salts 1. In the second part it was demonstrated that there is the possibility of reconverting the triazenes 3 into the starting stable dry salts 1 by using 5 as acid. The reactions were carried out in glacial acetic acid at 50-55 °C and normally afforded salts 1 in yields of around 90-99%. The third part concerns the setting up of two procedures for the conversion of 3 to aryl iodides 9, bromides 10 and chlorides 11. Procedure A used the corresponding aqueous hydrogen halides in acetonitrile at r.t. or 60 °C, sometimes in the presence of aqueous HBF4, sometimes Cu powder (25 examples, yields 65%-88%). Procedure B usually used anhydrous methanesulfonic acid and tetraalkylammonium halides in anhydrous acetonitrile at temperatures varying from r.t. to 80 °C, sometimes in the presence of Cu (16 examples, yields 65-88%).
Oxidation of dichloroanilines and related anilides catalyzed by iron(III) tetrasulfonatophthalocyanine
Hadasch, Anke,Meunier, Bernard
, p. 2319 - 2325 (2007/10/03)
We investigated the degradation of polychlorinated pollutants, such as dichloroanilines and related anilides, catalyzed by iron(III) tetrasulfonatophthalocyanine (FePcS) with potassium monopersulfate or hydrogen peroxide as oxidant. The reaction is influenced by the positions of the two chloro-substituents and by the nature of the oxidant. The FePcS- catalyzed oxidation of 3,5-dichloroaniline with potassium monopersulfate leads to the formation of more biodegradable products (carboxylic acids) and to potentially toxic dimers (azo and azoxy compounds). The oxidation of 3,4- dichloroaniline by FePcS/H2O2 converts this pollutant into coupling products. The formation of dimers in the catalytic oxidation of dichloroanilines can be avoided by acylation of the amine function.
Photochemistry and Photobiological Properties of Dicloran, a Postharvest Fungicide with Photosensitizing Side Effects
Bosca, Francisco,Miranda, Miguel A.,Serrano, Gabriel,Vargas, Franklin
, p. 532 - 537 (2007/10/03)
Photochemical and laser flash photolysis studies on dicloran have shown that this fungicide undergoes photoreactions such as photoreduction of the nitro group and homolytic rupture of the C-NH2 bond. Dramatic changes in the dicloran photoreactivity by the influence of the solvents have been observed. More efficient photodegradation of this fungicide was observed in diethyl ether and chloroform than in methanol or acetonitrile. Photoreduction of the nitro group from the dicloran triplet state seems to be the most important photodegradation pathway in solvents of low polarity. Hydrogen abstraction by the triplet state or the intermediate radicals appears to be in the origin of linoleic acid peroxidations photosensitized by dicloran. The photohemolysis assay has been used, as an in vitro phototoxicity test, to demonstrate the involvement of radical-mediated cellular membrane damage in dicloran photosensitization.
Ozone-mediated reaction of polychlorobenzenes and some related halogeno compounds with nitrogen dioxide: A novel non-acid methodology for the selective mononitration of moderately deactivated aromatic systems
Suzuki,Mori,Maeda
, p. 841 - 845 (2007/10/02)
In the presence of ozone and preferably methanesulfonic acid as catalyst, polychlorobenzenes undergo selective mononitration with nitrogen dioxide at low temperatures, giving the corresponding polychloronitrobenzenes, in most cases in nearly quantitative yields.
Multinuclear Magnetic Resonance Spectroscopic and Semiempirical Molecular Orbital (AM1) Studies of Substituted Anisoles
Pandiarajan, Karuppiah,Kabilan, Senthamaraikannan,Sankar, Punnaivanam,Kolehmainen,Erkki,Nevalainen, Tapio,Kauppinen, Reijo
, p. 2639 - 2646 (2007/10/02)
13C, 15N, and 17O NMR spectra have been recorded for 4-nitroanisole (1), its 2-methyl-, 2-chloro-, 2-bromo-, 2-iodo-, 2,6-diamethyl-, 2,6-dichloro, 2,6-dibromo-, and 2,6-diiodo-derivatives 2-9, also nitrobenzene (1a), its 3-methyl-, 3-chloro-, 3-bromo-, and 3-iodo-derivatives 2a-5a and 3,5-dichloro- and 3,5-dibromo-derivatives 7a and 8a.Analysis of the chemical shifts of carbon bearing nitro group and nitro oxygens in these compounds suggests that presence of one substituent ortho- to the methoxyl group enhances its resonance interaction with the benzene ring whereas presence of two ortho-substituents inhibits this resonance.However, in no case the resonance is completely inhibited.The extent of enhancement or inhibition is almost independent of the nature of the ortho-substituent.This conclusion has also been arrived by analyzing the reported chemical shifts of the para-carbons in anisoles 1b-9b and the corresponding carbons in benzene derivatives 1c-9c.Though evidence could not be obtained for steric enhancement of resonance using methoxyl oxygen chemical shifts, analysis of these chemical shifts in di-ortho-substituted anisoles 6-9 and 6a furnishes evidence for steric inhibition of resonance.However, 15N chemical shifts are of no use in studying these phenomena.Semiempirical molecular orbital calculations using AM1 Hamiltonian suggest that the methoxyl group is coplanar with the benzene ring in anisole, 4-nitroanisole and 2-substituted-4-nitroanisoles but is perpendicular to the benzene ring in 2,6-disubstituted-4-nitroanisoles.Moreover, in 2-substituted-4-nitroanisoles the O-methyl group is anti to the 2-substituent.
Magnetic susceptibilities of organic compounds: Part V - Influence of substituents on diamagnetic susceptibilities of disubstituted and trisubstituted benzenes
Baliah, V.,Jeyanthy, J. Judith Diana
, p. 472 - 476 (2007/10/02)
The magnetic susceptibilities of a number of triads of isomeric disubstituted benzenes have been determined, choosing the compounds in such a way that the substituents are present in the following combinations: (i) two electron-releasing substituents, (ii) a halogeno and an electron-releasing substituent, (iii) a halogeno and an electron-attracting substituent, and (iv) two halogeno substituents.The data show that for types (i), (ii) and (iv), the ortho isomers have the highest magnetic susceptibilities, the susceptibilities decreasing in the order: ortho > meta > para; for type (iii), the meta-isomers have the highest susceptibilities, the susceptibilities decreasing in the order: meta > para > ortho.The diamagnetic susceptibilities of some isomeric trisubstituted benzenes have also been determined and the data reveal that the susceptibility is the highest where the crowding of substituents is the highest (1,2,3-isomer) and lowest where the substituents are staggered and least crowded (1,3,5-isomer).Another observation made in the case of trisubstituted benzene is the applicability of a principle of additivity of their diamagnetic susceptibilities.
Reduction of Aryldiazonium Salts to Arenes
Lahoti, R. J.,Parameswaran, V.,Wagle, D. R.
, p. 767 - 769 (2007/10/02)
Aryldiazonium fluoroborates are smoothly reduced to the corresponding hydrocarbon derivatives by warming with DMF.When the amine has an electron donating substituent, the reaction proceeds at 65 deg C.When the amine has electron withdrawing substituents, the reaction proceeds rapidly at 25-45 deg C.Deamination of 2,4,6-trichlorobenzenediazonium fluoroborate with tetramethylurea gives acetaldehyde as an unexpected product together with 2,4,6-trichlorobenzene.The amines can also be deaminated with DMF without separation of the diazonium salt in aqueous or non-aqueous medium.
