65727-75-5Relevant academic research and scientific papers
A new and direct trifluoromethoxylation of aliphatic substrates with 2,4-dinitro(trifluoromethoxy)benzene
Marrec, Olivier,Billard, Thierry,Vors, Jean-Pierre,Pazenok, Sergii,Langlois, Bernard R.
, p. 2831 - 2837 (2010)
The reaction of tetrabutylammonium triphenyldifluorosilicate with 2,4-dinitro(trifluoromethoxy)benzene, in acetonitrile and under microwave irradiation, generates a trifluoromethoxide anion which is able to substitute activated bromides (benzyl bromide, cinnamyl bromide), as well as, to some extent, alkyl iodides. Aliphatic trifluoromethyl ethers are thus formed. This is the first example of the nucleophilic displacement of the trifluoromethoxy group from an activated aromatic ring.
Regioselective dinitration of simple aromatics over zeolite Hβ/nitric acid/acid anhydride systems
Smith, Keith,Alotaibi, Mohammad Hayal,El-Hiti, Gamal A.
, p. 107 - 123 (2014/04/17)
Various nitration systems comprising nitric acid, acid anhydride and zeolite H￡] in the absence of solvent are described. Direct double nitration of toluene with a nitric acid, propanoic anhydride and zeolite Hβ system has been developed to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6-dinitrotoluene ratio of 123:1. This system also nitrates activated mono-substituted benzenes (anisole and phenetole) and moderately activated mono-substituted benzenes (ethylbenzene and propylbenzene) to give mainly 2,4-dinitro derivatives. The zeolite can be recovered, regenerated and reused to give almost the same yield as that given when fresh zeolite is used. ARKAT-USA, Inc.
Highly regioselective dinitration of toluene over reusable zeolite Hβ
Smith, Keith,Alotaibi, Mohammad Hayal,El-Hiti, Gamal A.
, p. 244 - 247 (2013/02/22)
A nitration system comprising nitric acid, propanoic anhydride, and zeolite Hβ has been developed for dinitration of toluene to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6-dinitrotoluene ratio of over 120. This represents the most selective quantitative method for 2,4-dinitration of toluene; the catalyst is reusable, solvent is not needed, and an aqueous work-up is not required.
METHODS FOR THE NITRATION OF AROMATIC COMPOUNDS
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Page/Page column 13, (2012/05/04)
According to the invention there is provided a method for the nitration of an aromatic compound including the step of reacting the aromatic compound with nitric acid in the presence of an acid anhydride and an aluminosilicate catalyst, in which the acid anhydride is at least one of: ((CnH2n+1)CO)20, where n is 1 to 4 and the moiety CnH2n+1 can be straight or branched chain; ((CHpClq)CO)20, where p is 0 to 2, q is 1 to 3, and p+q = 3; and oxoiane -2, 5-dione, with the proviso that when the acid anhydride is (CH3CO)20, the aromatic compound is toluene, 2-nitrotoluene or 4-nitrotoluene, and the nitration is performed to produce 2,4-dinitrotoluene.
Regioselective nitration of arylboronic acids
Salzbrunn,Simon,Prakash,Petasis,Olah
, p. 1485 - 1487 (2007/10/03)
A convenient and simple regioselective ipso-nitration of arylboronic acids to nitroarenes has been developed. Under certain conditions even dinitro products were isolated.
Electrophilic ipso substitution of trimethylsilyl groups in fluorobenzenes
Coe, Paul L.,Stuart, Alison M.,Moody, David J.
, p. 27 - 32 (2007/10/03)
Using variants of literature methods 2,4- and 2,6- difluorophenyltrimethylsilanes have been bromodesilylated to the corresponding bromodifluorobenzenes in moderate to good yields, 3-bromo-2,6-difluorophenyltrimethylsilane afforded 1,3-dibromo-2,4-difluorobenzene whilst 1,3-difluoro-2,4-bis(trimethylsilyl)benzene yielded 3-bromo-2,6-difluorophenyltrimethylsilane. Application of either the Eaborn or Chvalovsky methods of nitrodesilylation to 4-fluorophenyltrimethylsilane, 2,4-difluorophenyltrimethylsilane and 2,6-difluorophenyltrimethylsilane afforded largely the corresponding desilylated products together with products associated with initial protodesilylation, followed by nitration of the resulting fluorobenzenes. The results obtained show that ipso desilylation in the fluoroaromatic series does follow the expected pattern previously obtained in the hydrocarbon analogues. They also show that in some cases the formation of unusually substituted fluoroarenes can be achieved more readily than by the methods previously used.
Catalysis in Nucleophilic Aromatic Substitution Reactions. The Presence of Molecular Complexes on the Pathway of Reactions between 1-Fluoro- and 1-Chloro-2,4-dinitrobenzene and Aliphatic Amines
Forlani, Luciano
, p. 1525 - 1530 (2007/10/02)
The kinetics of reactions between 1-halogeno-2,4-dinitrobenzene (halogen = F, Cl) and butylamine and piperidine were re-investigated in cyclohexane.The kobs values (s-1 mol-1 dm3) increased with increases in the initial concentration of the reacting amine.Investigation of the reaction mixtures at zero reaction time, indicated the presence of an interaction between the substrate and the amine which occurred in a rapidly established equilibrium and which preceded the substitution process.The nature of the molecular complexes observed is discussed.Present and previous data indicate that the kobs increase was difficult to explain with the traditional hypotesis of proton and leaving group departure as a rate determining step.A better rationalisation of the experimental data may be obtained by involving the molecular complexes on the substitution reaction pathway.
FLUORINATION BY USE OF TRANSITION METAL FLUORIDE-BIPYRIDINE COMPLEX IN APROTIC ORGANIC SOLVENTS
Sonoda, Hirosi,Sonoda, Takaaki,Kobayashi, Hiroshi
, p. 233 - 236 (2007/10/02)
Bipyridine complexes of transition metal fluorides which are soluble in aprotic organic sovents are used for the fluorination of organic halides under mild conditons.
