Anilines s. a. Amines

Amyl nitrite s. Alkyl nitrite Anhydronncleosides s. Cyclonucleosides 2,3-Anhydrosugars 29,101 Anilines (s. a. Amines, ar.)... 

Nitroso compounds are formed selectively via the oxidation of a primary aromatic amine with Caro s acid [7722-86-3] (H2SO ) or Oxone (Du Pont trademark) monopersulfate compound (2KHSO KHSO K SO aniline black [13007-86-8] is obtained if the oxidation is carried out with salts of persulfiiric acid (31). Oxidation of aromatic amines to nitro compounds can be carried out with peroxytrifluoroacetic acid (32). Hydrogen peroxide with acetonitrile converts aniline in a methanol solution to azoxybenzene [495-48-7] (33), perborate in glacial acetic acid yields azobenzene [103-33-3] (34). 

Zhang developed a monolithic poly(styrene-co-divinylbenzene) CEC column in which the EOF is supported by carboxyl groups of polymerized methacrylic acid [ 133]. Using benzene as a probe, column efficiencies of 90,000 -150,000 were observed within a flow velocity range of l-10cm/min (0.2-1.7 mm/s). Different families of compounds such as phenols, anilines, chlorobenzenes, phenylendi-amines, and alkylbenzenes were well separated typically in less than 5 min using 20 cm long columns. 

TMPD (k = 5.2 x 108 M 1s 1), p-diaminobenzene (k = 5 x 107 M 1s 1) and diphenylamine (k = lx 107 M 1 s 1) can all be readily converted into the corresponding radical cation by oxidation with pulse radiolysis generated SC>3 . With higher redox potential amines such as aniline and A. /V-dimethylandinc the oxidation to the radical cation fails32. Rate constants have also been measured for conversion of the same amines... 

Hydro acylation of alkenes was achieved in the presence of Wilkinson s catalyst and microwave irradiation under solvent-free conditions. As an example, benzaldehyde was reacted with dec- 1-ene to give 1-phenylundecan- 1-one in 83%yield within 30 min. Both domestic microwave ovens and single-mode reactors have been used for this reaction. The presence of an amine such as 2-amino-3-picoline or aniline and a carboxylic acid is crucial for the success of the reaction, showing that the formation of an imine plays an important role as an intermediate in the mechanism of this reaction29. 

Aniline is a weaker base than aliphatic amines because the lone pair of electrons is conjugated with the 7t-system of the aromatic ring and structures such as 11-13 contribute to the actual structure of aniline. Thus, the lone pair of electrons on the nitrogen atom is less available for coordination to a proton. The effect is considerable and aniline has a of 4.6 compared to methylamine s of 10.6 it thus reduces the basicity a million-fold. 

Reductive debromination of a-bromo- anda,a-dibromoketones.s a-Bromo- and a,a-dibromoketones are reductively debrominated when refluxed with N,N-dimethyl-aniline in an oil bath kept at 220°. Other amines, including triethylamine, N-methyl-aniline, and N,N-diethylaniline, fail to give appreciable amounts of dehalogenated product. Examples ... 

FIGURE 11.16 Electrophorogram for a standard solution of aromatic amines. Peaks 1, pyridine 2, /7-phenylenediamine 3, benzidine 4, o-toluidine 5, aniline 6, A/,A -dimethylaniline 7, p-anisidine 8, /7-chloroaniline 9, m-chloroaniline 10, ethylaniline 11, a-naphthylamine 12, diethyl-aniline 13, A -(l-naphthyl)ethylenediamine 14, 4-aminophenazone 15, o-chloroaniline 16, 3,4-dichloroani-line 17, 3,3 -dichlorobenzidine 18, 2-methyl-3-nitroaniline 19, 2,4-dichloroaniline 20, 2,3-dichloroaniline 21, 2,5-dichloroaniline. (From Cavallaro, A., Piangerelli, V., Nerini, F., Cavalli, S., and Reschiotto, C., J. Chromatogr., 709, 361-366, 1995.)... 

Several workers have employed features of the molecular electrostatic potential surface to study the pK s of amines. Nagy, Novak, and Aszasz [340] found good linear correlations between the pK s of pyridines, anilines, and aliphatic amines and the minima of the electrostatic potentials for these compounds. They used the CNDO/2 method [341] as well as a bond-increment method with data from Perrin s 1972 compilation [342] for their study. Using the bond-increment approach they found the following relationships ... 

Rapid aminations of 1-bromonaphthalenes with piperidine under microwave irradiation were reported by Hamann using Pd2(dba)3/rac. PPFA (Ar,AT-dimethyl-1-[2-(diphenylphosphanyl)ferrocenyl]ethylamine) precatalyst in combination with NaO-t-Bu in toluene at 120 °C (Scheme 92) [97]. Typically, reactions performed under conventional heating at 120 °C (oil bath) were still progressing after 16 h and were essentially complete by 24 h, whereas the microwave reactions appeared to be finished after 10 min. The same reaction conditions were also useful to functionalize 5- and 8-bromoquinolines with anilines and aliphatic amines (Schemes 93 and 94). Remarkably, no product formation was observed with S-bromo-S-cyanoquinohne and 5-bromo-8-methoxyquinoline under conventional heating for 24 h at the same temperature, while the desired 5-aminoquinohnes were smoothly obtained imder microwave irradiation in a reaction time of only 10 min. 

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