Aromatic amines tertiary

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). ... 

Nitrosation (Section 22 15) The reaction of a substance usu ally an amine with nitrous acid Pnmary amines yield dia zonium 10ns secondary amines yield N nitroso amines Tertiary aromatic amines undergo nitrosation of their aro matic ring... 

Reaction with Nitrous Acid. Primary, secondary, and tertiary aromatic amines react with nitrous acid to form a variety of products. Primary aromatic amines form diazonium salts. ... 

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

Basic Red 22 (134), which contains 1 part ia 7 of the yellowish red 1,4-dimethyl isomer, Basic Red 29 (135), and Basic Yellow 25 (136) are all examples of delocalized cationic azo dyes. Dyes of this type can also be synthesized by Hbnig s oxidative coupling reaction of heteroaromatic hydrazones with tertiary aromatic amines. 

The cure reaction of structural acrylic adhesives can be started by any of a great number of redox reactions. One commonly used redox couple is the reaction of benzoyl peroxide (BPO) with tertiary aromatic amines. Pure BPO is hazardous when dry [39]. It is susceptible to explosion from shock, friction or heat, and has an autoignition temperature of 79°C. Water is a very effective stabilizer for BPO, and so the initiator is often available as a paste or a moist solid [40], The... 

Ethyoxylates or propoxylates of p-toluidine are commonly used tertiary aromatic amines (Scheme 4). 

This compound is also described as diethanol-p-toluidine in the older literature. Anilines bearing hydroxyl groups are preferred because they are less volatile than anilines without polar substituents. Tertiary aromatic amines with para-halogen substitution have also been reported for use in adhesives [42]. 

It has been reported that tertiary aromatic amines can be encapsulated in formaldehyde-crosslinked microbeads, and used in an adhesive [54]. These microbeads burst when the joint is mated, and cure is accelerated. 

C-alkylation of secondary and tertiary aromatic amines by hexafluoroacetone or methyl trifluoropyruvate is performed under mild conditions [172] (equation 147) The reaction of phenylhydrazme with hexafluoroacetone leads selectively to the product of the C-hydroxyalkylation at the ortho position of the aromatic ring The change from the para orientation characteristic for anilines is apparently a consequence of a cyclic transition state arising from the initial N hydroxy alky lation at the primary amino group [173] (equation 148)... 

Nitrosodimethylaniline.—It is a peculiarity of the tertiary aromatic amines, which distinguish them fiom the corresponding aliphatic compounds, that they arc capable of reacting with nitrous acid. Here the nitroso-group replaces hydrogen in the para-position to the dimethylamino-group. 

The dienone, which is prepared essentially as described by Benedikt7 and Calo,8 monobrominates a wide range of primary, secondary, and tertiary aromatic amines almost exclusively in the para-position. The procedure described is of general synthetic utility for the preparation of para-brominated aromatic and heteroaromatic amines in high yields and frequently in a high state of purity. The submitters have used this technique to para-brominate many compounds in quantities... 

Secondly, the rates and modes of reaction of the intermediates are dependent on their detailed structure. For example, the stability of the cation radical formed by the oxidation of tertiary aromatic amines is markedly dependent on the type and degree of substitution in the p-position (Adams, 1969b Nelson and Adams, 1968 Seo et al., 1966), and the rate of loss of halogen from the anion radical formed during the reduction of haloalkyl-nitrobenzenes is dependent on the size and position of alkyl substituent and the increase in the rate of this reaction may be correlated with the degree to which the nitro group is twisted out of the plane of the benzene ring (Danen et al., 1969). 

Primary alkyl amines RNHi can be convertedto alkyl halides by (1) conversion to RNTs2 (p. 447) and treatment of this with I or Br in DMF, or to N(Ts)—NH2 derivatives followed by treatment with NBS under photolysis conditions, (2) diazotization with terr-butyl nitrite and a metal halide such as TiCU in DMF, or (3) the Katritzky pyrylium-pyridinium method (pp. 447,489). Alkyl groups can be cleaved from secondary and tertiary aromatic amines by concentrated HBr in a reaction similar to 10-71, for example,... 

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. " ... 

Phenols, secondary and tertiary aromatic amines, pyrroles, and indoles can be aminomethylated by treatment with formaldehyde and a secondary amine. Other aldehydes have sometimes been employed. Aminoalkylation is a special case of the Mannich reaction (16-15). When phenols and other activated aromatic compounds are treated withA-hydroxymethylchloroacetamide, amidomethylation takes place " ... 

Another hydroxylation reaction is the Elbs reaction In this method, phenols can be oxidized to p-diphenols with K2S20g in alkaline solution. Primary, secondary, or tertiary aromatic amines give predominant or exclusive ortho substitution unless both ortho positions are blocked, in which case para substitution is found. The reaction with amines is called the Boyland-Sims oxidation. Yields are low with either phenols or amines, generally under 50%. The mechanisms are not clear, but for the Boyland-Sims oxidation there is evidence that the S20 ion attacks at the ipso position, and then a migration follows. ... 

Crystalline Derivatives of Tertiary Aromatic Amines V. Picrates. Experimental details are given under Aliphatic Aminet, Section 111,123, 3. 

Sprenger HE, Ziegenbein W (1966) Condensation products of squaric acid and tertiary aromatic amines. Angew Chem Int Ed Engl 5 894... 

The indole- and benzindole-cyanine dyes illustrated in Scheme 6 are used by many major manufacturers in optical disk recording applications. These types of dye tend to be more light-stable than many other readily synthesized polymethine dyes. To increase the photostability, the dyes are used in combination with various types of stabilizers such as nickel dithiolato complexes and selected tertiary aromatic amine compounds.199 The application of cyanine dyes for optical storage media was primarily developed in Japan203 and several dyes and compatible stabilizers are commercially available in pure form from Japanese suppliers.199... 

It was soon realized that there are problems with this approach.24,25 Log ionization ratios for weak bases that are not primary aromatic amines, while linear in H0, do not give the unit slope required by equation (8). This soon led to many other acidity functions, defined for other types of weak base, HA for amides,24 Hq for tertiary aromatic amines,25 C0 or HR for carbocations,26,27 and so on. In a recent review of addity functions,28 28 different ones were listed... 

The luminescence of Re2Cl also is quenched by secondary and tertiary aromatic amines in acetonitrile solution(17). 

Julolidine (3) and benzoquinuclidine (4) can be considered as aniline derivatives with parallel and perpendicular electron lone-pairs, respectively. Relative to N,N-dimethylaniline (5), the simplest tertiary aromatic amine, the n orbital of julolidine is destabilized by 0.20 eV, while that of benzoquinuclidine is destabilized by 0.80 eV42. In the latter compound there is no n/jt conjugation while in the former it has a maximum value and, accordingly, the splitting of the first and the third IP is much smaller (0.70 eV) than in the former (2.55 eV) compound. 

The reaction of tertiary aromatic amines with butyl nitrite has been investigated in detail. The main products arise from 7V-dealkylation/7V-nitrosation, e.g. equation 91270. 

Siggia, S., Hanna, J. G., and Kervenski, J. R. Quantitative analysis of mistures of primary, secondary, and tertiary aromatic amines. Anal. Chem., 1950, 22, 1295-1297. 

Even such poor nucleophiles as tertiary aromatic amines react with 59 at elevated temperatures to give good yields of monosubstitution products such as 101 (76USP3963715). This reaction is analogous to the well-studied electrophilic substitution of a cyano group in tetracyanoethylene (102) by tertiary aromatic amines to give products 103 (63JCS4498) (Scheme 37). 

Treatment of Tertiary Aromatic Amines with Nitrous Acids. 

As indicated above, tertiary aromatic amines are directly C-nitrosated. The usual reagents are sodium nitrite and dilute hydrochloric acid, sodium nitrite and glacial acetic acid containing concentrated hydrochloric acid, and nitrite esters with hydrochloric acid [21a, 27]. While tertiary amines with such complex alkyl groups as found in A,A-di(3,5,5-trimethylhexyl)aniline are readily nitrosated [25], of the four A-butyl-A-methylaniline isomers, JV-r-butyl-A-methylaniline does not undergo the reaction, and even the nitroso compounds which did form were only unstable oils [27]. 

Whereas many tertiary aromatic amines are nitrosated quite simply at low temperatures with sodium nitrite and hydrochloric acid, with no particular attention to preparative details, some amines have to be nitrosated under con-... 

On treatment of certain other tertiary aromatic amines with nitrous acid, it has been found that either C-nitroso compounds, nuclear nitro compounds, or jV-nitrosoamines are formed with loss of an alkyl group. In the case of the nitrodimethylanilines, the latter two types of reaction may occur. The formation of nitro-jV-nitrosomethylanilines predominate at room temperature, whereas the formation of polynitro compounds predominates at more elevated temperatures. The formation of nitrosoamines from iVW-dimethylanilines appears to be particularly favored when both ortho positions are occupied by nitro groups, although /V-nitroso compounds were also obtainable from other nitrodimethylanilines. The product of the reaction, of course, is an /V-nitroso secondary amine. 

Tertiary aromatic amines may be nitrosated directly with nitrous acid, whereas primary aromatic amines normally are diazotized under these conditions. Some phenols may also be nitrosated under conditions similar to those used for the nitrosation of tertiary amines. 

Tertiary aromatic amines have also been nitrosated with pentyl nitrite in hydrochloric acid [21a],... 

---