O-aminoazobenzene

The phenomenon of azo—hydrazone tautomerism is firmly established75 in the benzeneazo-phenol, -naphthol, and -anthranol series, the azo form predominating in the first of these (65), the hydrazone form in the second (66), whilst the third exists exclusively in the hydrazone form (67). The situation is less clear in the analogous o-aminodiarylazo series. Thus, whilst it is known that o-aminoazobenzene (68) exists exclusively in the azo form, it has not been established whether... 

Diphenyltriazine is rearranged to form a mixture of p- and o- aminoazobenzene using nitric acid as a catalyst... 

Table 2.4 shows a comparison of the experimental and PPP-MO calculated electronic spectral data for azobenzene and the three isomeric monoamino derivatives. It is noteworthy that the ortho isomer is observed to be most bathochromic, while the para isomer is least bathoch-romic. From a consideration of the principles of the application of the valence-bond approach to colour described in the previous section, it might have been expected that the ortho and para isomers would be most bathochromic with the meta isomer least bathochromic. In contrast, the data contained in Table 2.4 demonstrate that the PPP-MO method is capable of correctly accounting for the relative bathochromicities of the amino isomers. It is clear, at least in this case, that the valence-bond method is inferior to the molecular orbital approach. An explanation for the failure of the valence-bond method to predict the order of bathochromicities of the o-, m- and p-aminoazobenzenes emerges from a consideration of the changes in 7r-electron charge densities on excitation calculated by the PPP-MO method, as illustrated in Figure 2.14. 

The role of N-sulfonyloxy arylamines as ultimate carcinogens appears to be limited. For N-hydroxy-2-naphthylamine, conversion by rat hepatic sulfotransferase to a N-sulfonyloxy metabolite results primarily in decomposition to 2-amino-l-naphthol and 1-sulfonyloxy-2-naphthylamine which are also major urinary metabolites and reaction with added nucleophiles is very low, which suggests an overall detoxification process (9,17). However, for 4-aminoazobenzene and N-hydroxy-AAF, which are potent hepatocarcinogens in the newborn mouse, evidence has been presented that strongly implicates their N-sulfonyloxy arylamine esters as ultimate hepatocarcinogens in this species (10,104). This includes the inhibition of arylamine-DNA adduct formation and tumorigenesis by the sulfotransferase inhibitor pentachlorophenol, the reduced tumor incidence in brachymorphic mice that are deficient in PAPS biosynthesis (10,115), and the relatively low O-acetyltransferase activity of mouse liver for N-hydroxy-4-aminoazobenzene and N-OH-AF (7,114,115). 

A striking feature of disperse dye development in recent decades has been the steady growth in bathochromic azo blue dyes to replace the tinctorially weaker and more costly anthraquinone blues. One approach is represented by heavily nuclei-substituted derivatives of N,N-disubstituted 4-aminoazobenzenes, in which electron donor groups (e.g. 2-acylamino-5-alkoxy) are introduced into the aniline coupler residue and acceptor groups (acetyl, cyano or nitro) into the 2,4,6-positions of the diazo component. A PPP-MO study of the mobility of substituent configurations in such systems demonstrated that coplanarity of the two aryl rings could only be maintained if at least one of the 2,6-substituents was cyano. Thus much commercial research effort was directed towards these more bathochromic o-cyano-substituted dyes. 

Azobenzene. o-Azotoluene. m-Azotoluene p-Azotoluene o-Azophenetole p-Azophenetole Benzeneazo-o-cresol a-Benzeneazo- P-naphthol P-Benzeneazo-a-naphthol 4-Benzeneazo- a-naphthol Benzeneazodiphenylamine a-Benzeneazo- P-naphthylamme 4-Benzeneazo- a-naphthylamme p-Aminoazobenzene p-Dimethylaminoazobenzene. p-Hydroxyazobenzene. ... 

If either the o- or -position is occupied, only one isomer is obtained transformation to the mefo-position does not occur. This is a standard method of preparation of acyl-amino-ketones, or by a further hydrolysis of amino-ketones. The tendency, illustrated in this reaction, of groups to wander from the amino group to the nucleus, is also shown in previous reactions and in the preparation of aminoazobenzene from diazoamino-benzene (Preparation 456), of sulphanilic acid from aniline sulphate (Preparation 292), of o- and p-chloroacetanilides from acetochloranilide (Preparation 328), of o- and p-toluidine from methylaniline hydrochloride, and of 1 2 4-aminodimethylbenzene (2 4-xylidine) from dimethylaniline hydrochloride. 

Disazo Dyes. About 10 % of all disperse dyes are disazo compounds [9], Even the simplest hydroxy disazo dyes, such as 4-aminoazobenzene coupled to phenol and 4-aminoazobenzene coupled to o-ere sol, have a good affinity for polyester fibers and yield lightfast reddish yellow hues. However, these shades are frequently less bright than those obtained with mono azo dyes. 

This hypotheses is further supported by a viscosity effect found by the same authors on the o/p-ratio of the rearrangement of 1,3-diphenyltriazene into 2- and 4-aminoazobenzene mixtures There is more ortho migration in solvents of higher viscosity. 

SYNS AAT o-AAT o-AMIDOAZOTOLUOL (GERMAN) AMINOAZOTOLUENE (indicator) o-AMINOAZOTOLUENE (MAK) 4 -AMINO-2,3 -AZOTOLUENE 4 -AMINO-2 3 -AZOTOLUENE o-AMINOAZOTOLUENO (SPANISH) o-AMINO-AZOTOLUOL 4-AMINO-2 ,3-DIMETHYL-AZOBENZENE 4 -AMINO-2,3 -DIMETHYL-AZOBENZENE o-AT BRASILAZINA OIL YELLOW R BUTTER YELI-OW C.1.11160 C.1.11160B C.I. SOLVENT YELLOW 3 2, 3-DIMETHYL-4-AMINOAZOBENZENE FAST GARNET GBC BASE FAST OIL YELLOW FAST YELLOW AT FAST YELLOW B HIDACO OIL YELLOW 2-METHYL-4-((2-METHYLPHENYL)-AZO)BENZENAMINE OAAT ... 

AMINO-9,10-ANTHRAQUINONE see AIBOOO O-AMINOANTHRAQUINONE see A1A750 P-AMINOANTHRAQUINONE see AIBOOO 2-AMINO-4-ARSENOSOPHENOL see OOKIOO AMINOARSON see CBJOOO AMINOAZOBENZENE see PEIOOO... 

Substitution of azobenzene by good electron-donating groups, (such as o- or p-amino groups) shifts the (7i,7t ) state far to the red, whereas the (n,7t ) is nearly constant in energy. Thus, azo compounds of the aminoazobenzene type are characterized by a close energetic proximity of the and n,jc )... 

Dimetbyl-4-aminoazobenzene 4-o-Tolylazo-o-toluidine C14H15N3 97-66-3 226.289 ye 11 (al) 102 vs etb, EtOH... 

Cancer of the liver, the first experimental visceral cancer, became a model of chemically induced cancer in 1933 when Yoshida induced liver tumors in rats and mice with oral administrations of o-aminoazotoluene (2, 3-dimethyl-4-aminoazobenzene) ( ). ... 

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