Aromatic amine secondary

The melting points of the derivatives of a number of selected primary and secondary aromatic amines are given in Tables IV, 100A and IV, 1OOB respectively. 

The melting points of some typical substituted aromatic amides are collected in Table IV,192. Other examples will be found in the appropriate columns of Tables IV,100A and B Primary and Secondary Aromatic Amines) and of Table IV,175 (Aromatic Carboxylic Acids). 

Some reference to the use of nitrous acid merits mention here. Primary aromatic amines yield diazonium compounds, which may be coupled with phenols to yield highly-coloured azo dyes (see Section IV,100,(iii)). Secondary aromatic amines afford nitroso compounds, which give Liebermann a nitroso reaction Section IV,100,(v). Tertiary aromatic amines, of the type of dimethylaniline, yield p-nitroso derivatives see Section IV,100,(vii). ... 

Several stabilizers are useful in minimizing oxidative degradation during thermoplastic processing or in the bulk soHd. Phenothiazine, hindered phenohc antioxidants such as butylated hydroxytoluene, butylatedhydroxyanisole, and secondary aromatic amines in concentrations of 0.01—0.5% based on the weight of polymer, are effective. 

The tendency of aliphatic ethers toward oxidation requires the use of antioxidants such as hindered phenoHcs (eg, BHT), secondary aromatic amines, and phosphites. This is especially tme in polyether polyols used in making polyurethanes (PUR) because they may become discolored and the increase in acid number affects PUR production. The antioxidants also reduce oxidation during PUR production where the temperature could reach 230°C. A number of new antioxidant products and combinations have become available (115,120,124—139) (see Antioxidants). 

Secondary aromatic amines form /V-nitrosamines and tertiary aromatic amines undergo ring nitrosation to yield C-nitroso products. 

Radical Scavengers Hydrogen-donating antioxidants (AH), such as hindered phenols and secondary aromatic amines, inhibit oxidation by competing with the organic substrate (RH) for peroxy radicals. This shortens the kinetic chain length of the propagation reactions. 

These compounds are used most frequentiy in combination with hindered phenols for a broad range of apphcations in mbber and plastics. They are also able to suppress color development caused by oxidation of the substrate and the phenoHc antioxidant. Unlike phenols and secondary aromatic amines, phosphoms-based stabilizers generally do not develop colored oxidation products. 

Dialkyl esters of 3,3 -thiodipropionic acid (53), cycHc phosphonites such as neopentylphenyl phosphite, derivatives of phosphaphenathrene-lO-oxide (54), secondary aromatic amines, eg, diphenylamine (55), and epoxidi2ed soybean oils (56) are effective stabili2ers for preventing discoloration of cellulose esters during thermal processing. 

Primary and secondary aromatic amines react with ethylene oxide to give the corresponding arylaminoethanols. 

The SEM derivative of a secondary aromatic amine, prepared from SEMCl (NaH, DMF, 0°, 100% yield), can be cleaved with HCl (EtOH, >88% yield). ... 

The well-known photopolymerization of acrylic monomers usually involves a charge transfer system with carbonyl compound as an acceptor and aliphatic tertiary amine, triethylamine (TEA), as a donor. Instead of tertiary amine such as TEA or DMT, Li et al. [89] investigated the photopolymerization of AN in the presence of benzophenone (BP) and aniline (A) or N-methylaniline (NMA) and found that the BP-A or BP-NMA system will give a higher rate of polymerization than that of the well-known system BP-TEA. Still, we know that secondary aromatic amine would be deprotonated of the H-atom mostly on the N-atom so we proposed the mechanism as follows ... 

The end group of the polymers, photoinitiated with aromatic amine with or without the presence of carbonyl compound BP, has been detected with absorption spectrophotometry and fluororescence spectrophotometry [90]. The spectra showed the presence of tertiary amino end group in the polymers initiated with secondary amine such as NMA and the presence of secondary amino end group in the polymers initiated with primary amine such as aniline. These results show that the amino radicals, formed through the deprotonation of the aminium radical in the active state of the exciplex from the primary or secondary aromatic amine molecule, are responsible for the initiation of the polymerization. 

The rate constant of Reaction 8.1 is much greater than the rate constant of Reaction 8.2, which means that antioxidants of this type can be used in very low concentrations with good effect. A typical thermoplastic would contain only 0.01-0.5% by mass of such an antioxidant. Typical compounds which work by this mechanism include substituted phenols and secondary aromatic amines. 

Ring nitrosation with nitrous acid is normally carried out only with active substrates such as amines and phenols. However, primary aromatic amines give diazonium ions (12-47) when treated with nitrous acid, " and secondary amines tend to give N-nitroso rather than C-nitroso compounds (12-49) hence this reaction is normally limited to phenols and tertiary aromatic amines. Nevertheless secondary aromatic amines can be C-nitrosated in two ways. The N-nitroso compound first obtained can be isomerized to a C-nitroso compound (11-32), or it can be treated with another mole of nitrous acid to give an N,C-dinitroso compound. Also, a successful nitrosation of anisole has been reported, where the solvent was CF3COOH—CH2CI2. " ... 

Tertiary (and to a lesser extent, secondary) aromatic amines can also be prepared in moderate to high yields by amination with an N-chlorodialkylamine (or an N-chloroalkylamine) and a metallic-ion catalyst (e.g., Fe, Ti, Cu, Cr ) in the presence of sulfuric acid. The attacking species in this case is the aminium radical ion R2NH- formed by ... 

Rearrangement of aryl triazenes can be used to prepare azo derivatives of primary and secondary aromatic amines." These are first diazotized at the amino group (see 11-4) to give triazenes, which are then rearranged by treatment with acid. The rearrangement always gives the para isomer, unless that position is occupied. 

Primary (R = H) and secondary aromatic amines react with alkenes in the presence of thallium(III) acetate to give vie- diamines in good yields. " The reaction is not successful for primary aliphatic amines. In another procedure, alkenes can be diaminated by treatment with the osmium compounds R2NOSO2 and R3NOSO (R = t-Bu)," analogous to the osmium compound mentioned at 15-51. The palladium-promoted method of 15-51 has also been extended to diamination. " Alkenes can also be diaminated indirectly by treatment of the aminomercurial compound mentioned in 15-51 with a primary or secondary aromatic amine. 

Phenols 7-Chloro-4-nitrobenzo-2-oxa-l,3-diazole (NBD chloride) Fluorescent 4-nitrobenzofuran derivatives are produced. Primary and secondary aromatic amines and thiols also react. [3]... 

Fluorescent 4-nitrobenzofuran derivatives are produced. Primary and secondary aromatic amines and thiols also react. 

PhNHj react in the presence of HgClj (5%) to produce the same anils as those obtained with the HgO/BFj.OEtj system (Eq. 4.63), but at room temperature and with a higher TOF (12 h ) [259]. Phenylacetylene and secondary aromatic amines afford enamines Hke those of Eq. (4.64), but ahphatic terminal alkynes and secondary aromatic amines give rise to a mixture of enamines (Eq. 4.65) [259]. 

Under the same conditions, the hydroamination of acetylene with primary or secondary aromatic amines brings about the formation of dimerization-cyclization products since the generated imines or enamines, respectively, are not stable. 

Primary aliphatic amines and piperidine react even at room temperature, whereas secondary aliphatic amines require reflux temperature. Primary and secondary aromatic amines also require reflux temperature and A -methylimidazole as catalyst. 

The difference in position of attack on primary and secondary aromatic amines, compared with phenols, probably reflects the relative electron-density of the various positions in the former compounds exerting the controlling influence for, in contrast to a number of other aromatic electrophilic substitution reactions, diazo coupling is sensitive to relatively small differences in electron density (reflecting the rather low ability as an electrophile of PhN2 ). Similar differences in electron-density do of course occur in phenols but here control over the position of attack is exerted more by the relative strengths of the bonds formed in the two products in the two alternative coupled products derivable from amines, this latter difference is much less marked. 

El-Kommos and Emara [44] described a spectrophotometric method, for the determination of primaquine and other secondary aromatic amines pharmaceuticals, using 3-methylbenzothiazolin-2-one hydrazone. The method is based on oxidative coupling reaction of 3-methylbenzothiazolin-2-one hydrazone. 

El-Kommos and Emara [47] determined primaquine and other secondary aromatic amines pharmaceuticals by a spectrophotometric method using 4-dimethyl amino cinnamaldehyde. The reaction of the reagent with primaquine and with the other amines was investigated. Powdered tablets were extracted with methanolic 0.1 M perchloric acid. The extract was mixed 1 1 with methanolic 0.2% of 4-dimethyl amino cinnamaldehyde and the mixture was diluted with methanol before measurement of the absorbance at 670 nm for primaquine phosphate. Beer s law was obeyed for 2-20 pg/mL of primaquine. The pink and green color formed with primaquine was stable for at least 24 h. Recoveries were good. Amodiaquine did not interfere with the determination of primaquine. 

The name given to certain nitroso-secondary aromatic amines which, added in small quantities to butyl rubber, result in improved resilience and higher tensile strength. 

Carpentier and Lemetais60 have published ionization ratios for the protonation of some secondary aromatic amines in aq. H2S04, and these are illustrated as an excess acidity plot (log I - log Cn > vs. X, using the values in Table 3) in Fig. 4. In all the calculations in this section the data have been weighted using an... 

Table 9 Intercept p bh+ values and m slopes for some secondary aromatic amines in...

Vardanyan [65,66] discovered the phenomenon of CL in the reaction of peroxyl radicals with the aminyl radical. In the process of liquid-phase oxidation, CL results from the disproportionation reactions of primary and secondary peroxyl radicals, giving rise to trip-let-excited carbonyl compounds (see Chapter 2). The addition of an inhibitor reduces the concentration of peroxyl radicals and, hence, the rate of R02 disproportionation and the intensity of CL. As the inhibitor is consumed in the oxidized hydrocarbon the initial level of CL is recovered. On the other hand, the addition of primary and secondary aromatic amines to chlorobenzene containing some amounts of alcohols, esters, ethers, or water enhances the CL by 1.5 to 7 times [66]. This effect is probably due to the reaction of peroxyl radicals with the aminyl radical, since the addition of phenol to the reaction mixture under these conditions must extinguish CL. Indeed, the fast exchange reaction... 

Another drug that is associated with a relatively high incidence of both drug-de-pendent and autoimmune antibodies is diclofenac [38], In some cases the specificity of the diclofenac-induced autoantibodies is very similar to that induced by a-methyldopa [39], Diclofenac is a secondary aromatic amine and is oxidized to reactive metabolites by both cytochromes P450 and myeloperoxidase [40], When patient sera were tested, it was addition of the 4-hydroxy metabolite that most commonly led to agglutination of red cells [41] this metabolite has the potential to be air oxidized to a reactive iminoquinone. 

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