18490-44-3Relevant academic research and scientific papers
Conversion of anilines into azobenzenes in acetic acid with perborate and Mo(VI): correlation of reactivities
Karunakaran,Venkataramanan
, p. 375 - 385 (2019/02/14)
Azobenzenes are extensively used to dye textiles and leather and by tuning the substituent in the ring, vivid colours are obtained. Here, we report preparation of a large number of azobenzenes in good yield from commercially available anilines using sodium perborate (SPB) and catalytic amount of Na2MoO4 under mild conditions. Glacial acetic acid is the solvent of choice and the aniline to azobenzene conversion is zero, first and first orders with respect to SPB, Na2MoO4 and aniline, respectively. Based on the kinetic orders, UV–visible spectra and cyclic voltammograms, the conversion mechanism has been suggested. The reaction rates of about 50 anilines at 20–50?°C and their energy and entropy of activation conform to the isokinetic or Exner relationship and compensation effect, respectively. However, the reaction rates, deduced by the so far adopted method, fail to comply with the Hammett correlation. The specific reaction rates of molecular anilines, obtained through a modified calculation, conform to the Hammett relationship. Thus, this work presents a convenient inexpensive non-hazardous method of preparation of a larger number of azobenzenes, and shows the requirement of modification in obtaining the true reaction rates of anilines in acetic acid and the validity of Hammett relationship in the conversion process, indicating operation of a common mechanism.
Catalytic C-H Amination with aromatic amines
Gephart III, Raymond T.,Huang, Daria L.,Aguila, Mae Joanne B.,Schmidt, Graham,Shahu, Andi,Warren, Timothy H.
supporting information; experimental part, p. 6488 - 6492 (2012/07/30)
Aniline joins the club: A β-diketiminato copper(I) catalyst enables C-H amination of anilines employing low catalyst loadings to preclude oxidation to the diazene ArNi-NAr (see scheme). Electron-poor anilines are particularly resistant towards diazene formation and participate in the amination of strong and unactivated C-H bonds. N-alkyl anilines also take part in C-H amination. Copyright
Cycloaddition reactions of 1,3-diaza-2-azoniaallene salts and glycals
Weng, Min,Geyer, Armin,Friemel, Anke,Jochims, Johannes C.,Lutz, Martin
, p. 486 - 493 (2007/10/03)
The 1,3-diaza-2-azoniaallene salt 3a reacts stereoselectively with glycals (5a-e) to afford pyrano[2,3-d]-1,2,3-triazolium salts 6a-e. In contrast to other 1,3-dipolar cycloadditions of glycals reported so far, the stereoselectivity of compounds 6 is not determined by the substituent on C-3 of the glycal. Both cis (6a,b) and trans (6d,e) substitutions on C-7 and C-7a were found for bicyclic compounds 6 (crystal structure of 6a). Under the influence of acid 6e opens the pyran ring to give the triazolium salt 9. Addition of antimony pentachloride to a solution of the glycal 5e and the chlorotriazene 2a results in the formation of the pyranotriazene 12 containing two triazene units. In the presence of acid the pyranotriazene 6c reacts with alcohols to afford 2-hydrazino glycosides 13a,b, 15, which with zinc dust in acetic acid are reduced to 2-amino glycosides 14a,b. Wiley-VCH Verlag GmbH, 2000.
OXYDATION PERMANGANIQUE ASSISTEE PAR TRANSFERT DE PHASE D'AMINES AROMATIQUE PRIMAIRES
Hedayatullah, Mir,Roger, Annie
, p. 59 - 62 (2007/10/02)
Phase-transfer-assisted permanganate oxidation of primary aromatic amines with optimisation of the process conditions permits the selective synthesis of the corresponding azo compounds.Theses procedures, owing to their good yields, constitute a considerab
27. Magnetic-Field Effect in Aromatic Dediazoniation
Laali, Kenneth K.,Gao, Hong
, p. 304 - 308 (2007/10/02)
Homolytic dediazoniation of tribromo- and trichloro-benzenediazonium tetrafluoroborates in highly ionizing, low-nucleophilicity solvents (trifluoroethanol and trifluoromethanesulfonic acid (TfOH)) exhibits a strong magnetic-field dependency of dediazoniation products; a more facile singlet-to-triplet intersystem crossing results in increased radical-escape products at higher magnetic fields.
OXIDATION OF AROMATIC AMINES WITH CHROMYL CHLORIDE - I OXYDATION OF AROMATIC PRIMARY AMINES
Nallaiah, C.,Strickson, J. A.
, p. 4083 - 4088 (2007/10/02)
The oxidation of aromatic primary amines with chromyl chloride in carbon tetrachloride or chloroform, results in the formation of intermediate solid adducts (Etard adducts) which, on hydrolysis, give azobenzenes(1), 1,4-benzoquinones(2), anilino-1,4-benzoquinones(3), 1,4-benzoquinone anils(4) and anilino-1,4-benzoquinone anils(5) in yields which depend on the position, nature and degree of substitution of the ring.
New Azoolefines and their Acidic Cleavage to Aryldiimines
Kirschke, Klaus,Moeller, Angela,Schmitz, Ernst
, p. 893 - 898 (2007/10/02)
3-Amino-1-aryl-3',3'-dimethyl-pyrazolin-4-spiro-2'-oxiran-5-ones (3a-c) undergo ring opening with methoxide forming methyl 3-amino-3-arylazo-propenoates (5a-c). 5a-c are cleaved under acidic conditions.The main products of the cleavage of 5c with methanolic hydrochloric acid are nitrogen, 2,4,6-trichloro-benzene (6), 2,4,6-trichloro-aniline (9) and 2,4,6-trichloro-phenylhydrazine (10).Intermediates of the cleavage of 5 are aryldiimines trapped with benzaldehyde as the corresponding benzhydrazides (12a,b).
