- Preparation method of N-methyl-4-bromoaniline
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The invention provides a preparation method of N-methyl-4-bromoaniline, belonging to the technical field of organic synthesis. The preparation method solves the technical problems that existing monomethylation reaction steps of aniline are tedious and the purity of prepared products is low. The method comprises the following steps: 1, adding dichloroethane and N-methylaniline into a first reactor,then dropwise adding acetic anhydride into the first reactor, and carrying out stirring; 2, dropwise adding a brominating agent into the formed reaction system, carrying out stirring, carrying out sampling analysis until the content of N-methyl acetanilide is less than 1%, adding sodium sulfite, carrying out stirring, and carrying out suction filtration; 3, adding the solid N-methyl-4-bromoacetanilide obtained through suction filtration in the step 2 into a second reactor, then adding hydrochloric acid with a mass concentration of 15%, carrying out heating reflux for 3 h, and carrying out sampling analysis until a reaction is completed; and 4, cooling, neutralizing and extracting the reaction system in the step 3, and recovering the solvent to obtain the colorless transparent liquid N-methyl-4-bromoaniline. The N-methyl-4-bromoaniline prepared by using the method is high in purity, and has a content of greater than 98%.
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Paragraph 0066-0068
(2019/12/25)
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- Cu-mediated selective bromination of aniline derivatives and preliminary mechanism study
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A simple and efficient bromination of aniline, aniline derivatives, and analogs have been developed. Forty three examples were given and the highest yield reached was 98%. Different substrates including substituted aniline, pyridin-amine, N-substituted aniline, N,N-disubstituted aniline, N-phenyl-amide, N-phenyl-sulfonamide, and nitrogen-containing heterocycles were all reactive and selectively generated desired bromo-products. The method can be applied to synthesize drug intermediate and quinoxaline derivatives.
- Zhao, Hong-Yi,Yang, Xue-Yan,Lei, Hao,Xin, Minhang,Zhang, San-Qi
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supporting information
p. 1406 - 1415
(2019/05/01)
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- Practical and metal-free electrophilic aromatic halogenation by interhalogen compounds generated in situ from N-halosuccinimide and catalytic TMSCL
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Halomonochloride compounds (ClCl, BrCl, ICl) generated in situ from N-halosuccinimide and catalytic chlorotrimethylsilane (TMSCl, 0.1 equiv) can efficiently halogenate aromatic compounds to give halogenated products in good to excellent yields and selectivities. The reaction can be carried out at room temperature or at lower temperatures, requires only one hour, is practical to apply to a wide range of substrates, and provides a simple access to a variety of haloarene compounds. Georg Thieme Verlag Stuttgart New York.
- Maibunkaew, Tapanee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Bunrit, Anon,Ruchirawat, Somsak
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supporting information
p. 1769 - 1775
(2014/08/05)
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- Selective bromination of pyrrole derivatives, carbazole and aromatic amines with DMSO/HBr under mild conditions
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Bromination of pyrrole derivatives, carbazole and aromatic amines using the DMSO/HBr system affords high yields of the corresponding bromo compounds. Temperature control used in the bromination of anilines helped to promote selective formation of mono- or di-brominated products. Simple operation, low toxicity and high selectivity make this a promising new procedure for the bromination of aromatic compounds.
- Liu, Cong,Dai, Rongji,Yao, Guowei,Deng, Yulin
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p. 593 - 596
(2015/01/09)
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- Functionalized analogues of Tr?ger's base: scope and limitations of a general synthetic procedure and facile, predictable method for the separation of enantiomers
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A major stumbling block in the applications of enantiomerically pure Tr?ger's base analogues is their poor availability. We have therefore developed a facile method for the enantioseparation of functionalized Tr?ger's base analogues possessing various sub
- Didier, Delphine,Tylleman, Beno?t,Lambert, Natacha,Vande Velde, Christophe M.L.,Blockhuys, Frank,Collas, Alain,Sergeyev, Sergey
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p. 6252 - 6262
(2008/09/21)
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- FLUORESCENT CHEMICAL COMPOUNDS HAVING HIGH SELECTIVITY FOR DOUBLE STRANDED DNA, AND METHODS FOR THEIR USE
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Chemical compounds having a high selectivity for double stranded DNA over RNA and single stranded DNA are disclosed. The chemical compounds are stains that become fluorescent upon illumination and interaction with double stranded DNA, but exhibit reduced
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Page/Page column 20
(2008/06/13)
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- 1-Benzyl-4-aza-1-azoniabicyclo[2.2.2] octane tribromide as a highly reactive brominating agent for aniline derivatives
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Reaction of anilines with 1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octane tribromide (3) in the presence of CaCO3 in small amounts of methanol gave brominated aromatic amines in good yields at room temperature. The isolation of products is straightforward.
- Hajipour,Imanieh,Pourmousavi
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p. 4597 - 4604
(2007/10/03)
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- KINETICS AND MECHANISM OF SOLVOLYSIS OF N-ARYL SULFURIC DIAMIDES
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The methanolysis and hydrolysis kinetics have been studied with the following sulfuric diamide derivatives: N-methyl-N-phenyl- (IIIa), N-methyl-N-(4-methoxycarbonylphenyl)- (IIIb), N-(4-methoxycarbonylphenyl)- (IIIc), N-methyl-N-(2-methoxycarbonylphenyl)- (IIId), N-(2-methoxycarbonylphenyl)- (IIIe), and N-methyl-N-(2,4-dibromophenyl)- (IIIf).The solvolyses of the neutral substrates IIIa and IIIb proceed by the addition-elimination mechanism.In the presence of the solvent lyate ions the solvolyses go by the E1cb mechanism.The solvolyses of the conjugated bases ofcompounds IIIa and IIIb are subject to general acid catalysis, the effects of the ring substituents being opposite to those in the addition-elimination mechanism.The solvolyses of compounds IIId and IIIf exhibit a distinct catalytic effect of neighbouring group; the reaction goes via a reactive intermediate, the transformation of the intermediate into the solvolysis product being subject to general acid and base catalysis.
- Kavalek, Jaromir,Kralikova, Ulrika,Machacek, Vladimir,Sedlak, Milos,Sterba, Vojeslav
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p. 202 - 222
(2007/10/02)
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- Bromation regioselective en serie aromatique. I: Monobromation en position para de phenols et d'amines aromatiques par le tribromure de tetrabutylammonium
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The reaction of tetrabutylammonium tribromide (TBABr3) with phenols and aromatic amines in aprotic and non-basic solvents at 20 deg C gives exclusively the corresponding para-brominated compounds in high yields.A mechanism involving electrophilic substitution by the tribromide anion Br3- itself is suggested to account for the results, especially the regioselective para bromination.Key words: bromination, tetrabutylammonium tribromide, phenols, aromatic amines.
- Berthelot, Jacques,Guette, Catherine,Desbene, Paul-Louis,Basselier, Jean-Jacques,Chaquin, Patrick,Masure, Daniel
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p. 2061 - 2066
(2007/10/02)
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- REGIOSELECTIVE MONOBROMINATION OF AROMATIC AMINES WITH TETRABUTYLAMMONIUM TRIBROMIDE
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A simple and efficient method for monobromination of aromatic amines predominantly in the para position is reported.Tetrabutylammonium tribromide is used at 20 deg C and yields of parabromoanilines are higher than 90percent.
- Berthelot, J.,Guette, C.,Essayegh, M.,Desbene, P.L.,Basselier, J.J.
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p. 1641 - 1646
(2007/10/02)
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- Aminobenzenes, XVII. Addition Products of N,N-Dialkylanilines and Bromine - Synthesis and Reactions
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4-Bromo-N,N-dialkylanilines 1 react with bromine in inert solvents to give the 1:1 addition compounds 2 or 3.IR and UV investigations established the structure of the isolated products to be CT complexes (? complexes) for 2 and N-bromoanilinium bromides for 3.The adducts 2 react to yield substitution products 6 and dealkylation products 7 in polar solvents (dimethylformamide, acetic acid, methanol), whereas the main product from 2a by reaction in acetone is N,N,N',N'-tetramethylbenzidine (9).Radical cations 10 are postulated to be the determining intermediates for these reactions.The tendency of the alkyl groups to be cleaved off decreases in the order isopropyl > ethyl > methyl.Under analogous conditions the N-bromo compounds 3 give predominantly the anilines 1 and only small amounts of substitution products 6, dealkylation and reaction to benzidines were not observed.
- Effenberger, Franz,Steinbach, Adalbert,Epple, Gerhard,Hanauer, Johann
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p. 3539 - 3551
(2007/10/02)
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- Alkyl Nitrite-Metal Halide Deamination Reactions. 7. Synthetic Coupling of Electrophilic Bromination with Substitutive Deamination for Selective Synthesis of Multiply Brominated Aromatic Compounds from Arylamines
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Aromatic amines undergo substitution with copper(II)bromide that is in competition with substitutive deamination when these reactions are performed with tert-butyl nitrite.Except for the exceptionally reactive 4-substituted 1-aminonaphthalenes,which undergo selective bromine substitution at the 1- and 2-positions in relatively high isolated yields,rates for oxidative bromination and substitutive deamination are not sufficiently different that selective multiple bromination can be achieved.Oxidative bromination of N,N-dimethylaniline by copper(II)bromide occurs with partial dealkylation,and nitration products are observed from reactions performed with copper(II)bromide and tert-butyl nitrite.Implications of these results for the successful utilization of copper(II)bromide/tert-butyl nitrite combinations in substitutive deamination reactions of aromatic amines are discussed.Multiply brominated aromatic compounds are produced from aromatic amines in high yield through treatment of the aromatic amine with the combination of molecular bromine and catalytic quantities of copper(II)bromide and,following a normally brief time delay,with tert-butyl nitrite.All unsubstituted aromatic ring positions ortho and para to the amino group,as well as the position of the amino group,are substituted by bromine.The only observed byproducts from use of this procedure (usually 2percent yield) are the partially brominated benzene derivatives.
- Doyle, Michael P.,Lente, Michael A. van,Mowat, Rex,Fobare, William F.
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p. 2570 - 2575
(2007/10/02)
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