Anilines aniline derivatives

Nonlinear optical properties of homopolymers and copolymers synthesized by enzyme-catalyzed reactions in monophasic media are given in Table 2. Aromatic monomers used for the polymerizations are aniline, aniline derivatives, and phenol derivatives. The table also gives x values of a number of monomers (used in the polymerization reactions) and solvent mixtures used to prepare polymer solutions for the measurements. In general, the third-order susceptibilities of all monomers and solvents tested are very low and are in the neighborhood of 10" esu. The values of the aromatic polymers obtained are three to five orders higher than the values of the monomers. Third-order nonlinear susceptibilities of homopolymers synthesized (by enzyme-catalyzed reactions) from aromatic amines such as aniline, benzidine, ethylaniline, propylaniline, butylaniline, and dimethy-... 

The diazonium salts 145 are another source of arylpalladium com-plexes[114]. They are the most reactive source of arylpalladium species and the reaction can be carried out at room temperature. In addition, they can be used for alkene insertion in the absence of a phosphine ligand using Pd2(dba)3 as a catalyst. This reaction consists of the indirect substitution reaction of an aromatic nitro group with an alkene. The use of diazonium salts is more convenient and synthetically useful than the use of aryl halides, because many aryl halides are prepared from diazonium salts. Diazotization of the aniline derivative 146 in aqueous solution and subsequent insertion of acrylate catalyzed by Pd(OAc)2 by the addition of MeOH are carried out as a one-pot reaction, affording the cinnamate 147 in good yield[115]. The A-nitroso-jV-arylacetamide 148 is prepared from acetanilides and used as another precursor of arylpalladium intermediate. It is more reactive than aryl iodides and bromides and reacts with alkenes at 40 °C without addition of a phosphine ligandfl 16]. 

A Pd-cataly2ed reaction of amines with halides is expected, but actually little is known about the reaction. The CDE ring system of lavendamycin (805) has been constructed by the intramolecular reaction of aryl bromide with aniline derivative in 804, but 1.2 equiv, of Pd(Ph3P)4 is required[679]. 

Category Ic cyclizations involve formation of the C3-C3a bond and require aniline derivatives with a nitrogen substituent appropriate for such reaction. Some, but not all, such cyclizations also require an o-substituent, frequently halogen. The rctrosynthetic transformations corresponding to the most important of this group of syntheses are shown in Scheme 4.1... 

In aniline derivatives (458) the mechanism of this reaction is still not fully settled (459-461). However, the latest results seem to favor a pathway that, applied to 2-nitraminothiazole, would give Scheme 138, where the key step is the formation of a radical ion (223). Reexamination of the original reports on this reaction (16, 374, 378. 462) with EPR and Chemically Induced Dynamic Nuclear Polarisation techniques could be fruitful. 

Aniline was first isolated in 1826 as a degradation prod uct of indigo a dark blue dye obtained from the West Indian plant Indigofera anil from which the name aniline IS derived... 

Textile dyes were, until the nineteenth century invention of aniline dyes, derived from biological sources plants or animals, eg, insects or, as in the case of the highly prized classical dyestuff Tyrian purple, a shellfish. Some of these natural dyes are so-caUed vat dyes, eg, indigo and Tyrian purple, in which a chemical modification after binding to the fiber results in the intended color. Some others are direct dyes, eg, walnut sheU and safflower, that can be apphed directly to the fiber. The majority, however, are mordant dyes a metal salt precipitated onto the fiber facUitates the binding of the dyestuff Aluminum, iron, and tin salts ate the most common historical mordants. The color of the dyed textile depends on the mordant used for example, cochineal is crimson when mordanted with aluminum, purple with iron, and scarlet with tin (see Dyes AND DYE INTERMEDIATES). 

Rubber chemicals, primarily antioxidants (qv), stabiLhers, and antio2onants (qv), account for 12% of the demand for aniline woddwide. Important agricultural uses for aniline derivatives include fungicides, insecticides, animal repellents, and defoHants. It is estimated that less than 5% of the aniline produced in 1988 was consumed for agricultural chemicals. 

Production figures for the aminophenols are scarce, the compounds usually being classified along with many other aniline derivatives (86). Most production of the technical grade materials (95% purity) occurs on-site as they are chiefly used as intermediate reactants in continuous chemical syntheses. World production of the fine chemicals (99% purity) is probably no more than a few hundred metric tons yearly, at prices of about 45 per kg in 1990. 

Guanidines. Guanidines (10) were one of the first aniline derivatives used as accelerators. They are formed by reaction of two moles of an aromatic amine with one mole of cyanogen chloride. Diphenylguanidine (DPG) has enjoyed a resurgence ia demand as an activator for sulfenamides and a co-accelerator ia tire tread compounds which employ siUca fillers for low rolling resistance. Guanidines alone show too Htde activity to be extensively used as primary accelerators. There were no U.S. producers as of mid-1996. 

Isocyanates. The commodity isocyanates TDI and PMDI ate most widely used in the manufacture of urethane polymers (see also Isocyanates, organic). The former is an 80 20 mixture of 2,4- and 2,6-isomers, respectively the latter a polymeric isocyanate obtained by phosgenation of aniline—formaldehyde-derived polyamines. A coproduct in the manufacture of PMDI is 4,4 -methylenebis(phenyHsocyanate) (MDI). A 65 35 mixture of 2,4- and 2,6-TDI, pure 2,4-TDI and MDI enriched in the 2,4 -isomer are also available. The manufacture of TDI involves the dinitration of toluene, catalytic hydrogenation to the diamines, and phosgenation. Separation of the undesired 2,3-isomer is necessary because its presence interferes with polymerization (13). 

The o-nitrobenzyl and p-nitrobenzyl ethers can b prepared and cleaved by many of the methods described for benzyl ethers. The p-nitrobenzyl ether is also prepared from an alcohol and p-nitrobenzyl alcohol (trifluoroacetic anhydride, 2,6-lutidine, CH2CI2, 67% yield). In addition, the o-nitrobenzyl ether can be cleaved by irradiation (320 nm, 10 min, quant, yield of carbohydrate " 280 nm, 95% yield of nucleotide ). The p-nitrobenzyl ether has been cleaved by electrolytic reduction (—1.1 V, DMF, R4N X, 60% yield) and by reduction with Na2S204 (pH 8-9, 80-95% yield). These ethers can also be cleaved oxidatively (DDQ or electrolysis) after reduction to the aniline derivative. ... 

Certain reactions between carbonyl compounds and nucleophiles are catalyzed by amines. Some of these reactions are of importance for forming carbon-carbon bonds, and these are discussed in Chapter 2 of Part B. The mechanistic principle can be illustrated by considering the catalysis of the reaction between aldehydes and hydroxylamine by aniline derivatives. 

Therefore it is possible to determine absorption spectra directly on the TLC plate by comparison with a substance-free portion of the layer. The wavelengths usually correspond to the spectra of the same substances in solution. However, adsorbents (silanols, amino and polyamide groups) and solvent traces (pH differences) can cause either bathochromic (ketones, aldehydes [60, 61], dyestuffs [62]) or hypsochromic (phenols, aniline derivatives [63]) shifts (Fig. 23). 

Phenylurea herbiades are first hydrolyzed to the corresponding aniline derivatives and then reacted at the start with 4 pi 0 25% dansyl chlonde solution... 

The Hegedus indole synthesis involves one of the earlier (formal) examples of olefin hydroamination. An ortho-vinyl or ortho-nllyl aniline derivative 1 is treated with palladium(II) to deliver an intermediate resulting from alkene aminopalladation. Subsequent reduction and/or isomerization steps then provide the indoline or indole unit 2, respectively. 

P-amino acid products. Treatment of oxazoline 53 with 7V-lithiopiperidine followed by alkylation with iodomethane affords aniline derivative 54 in 94% yield and 99% de. Hydrolysis of the oxazoline group provided amino acid 55 in 92% yield and >99% ee. 

A number of dihydroquinolines have been prepared by treating aniline derivatives with acetone or mesityl oxide in the presence of iodine. In these cases aromatization to the fully unsaturated quinoline would require the loss of methane, a process known as the Riehm quinoline synthesis. Such Skraup/Doebner-von Miller-type reactions are often low yielding due to large amounts of competing polymerization. For example, aniline 37 reacts with mesityl oxide to give dihydroquinolines 39, albeit in low yield. ... 

Indoles 118 (99IZV400, 99RCB398) and indolizines 120 (99IZV2375, 99RCB2349) have been obtained by the condensation of suitably functionalized pyridinium salts 119 and aniline derivatives (Scheme 71). 

Tamaoku and colleagues presented an efficient enzymatic photometric determination of hydrogen peroxide ffiat is essentially a color reaction resulting from the oxidative condensation of A/-ethyl-A/-(2-hydroxy-3-sulfopropyl)aniline derivatives wiffi 4-aminoantipyrine in the presence of hydrogen peroxide and peroxidase (82CPB2492). A similar calorimetric detection of hydrogen peroxide has been patented (83GEP3301470). 

Reaction of aniline derivatives with 4-chlorobutyroyl chloride followed by cyclization with sodium ethoxide and subsequent thionation promoted by sonication gave the corresponding A -arylpyrrolidine-2-thiones 126. Zinc-mediated condensation of diethyl bromomalonate with 126 using iodine as activator gave the vinylogous urethanes 127 whose cyclization with PPA gave the tricyclic compound 128 which upon hydrolysis afforded the acid 129 (96TL9403). 

The aniline derivative 332, prepared from 2-fluoro-6-nitrotoluene, was transformed through successive reactions as shown in Scheme 60 to give the functionalized indole 333. It was then reduced with LiAlH4 to the dimethylaminopropyl derivative which was quaternized with Mel to the trimethyl ammonium salt 334. Subsequent cyclization and functionalization afforded the pyrroloquinoline 335. The latter could be transformed to the tetracyclic acid 336 (90JHC2151). (Scheme 60)... 

A simple aniline derivative acts as a prostatic antiandro-t (>n. Its synthesis involves simple acylation of disubstituted iiriiline 13 with isobutyryl chloride to give flutamide (14). 

A compound closely related to classical adrenergic agonists in which the para hydroxy function is however replaced by an amino group has been investigated for its activity as a growth promoter in domestic animals. Acylation of the aniline derivative 26 with chloracetyl chloride will afford acetophenone 27 the amino-ketone 28 is obtained on reaction with isopropylamine. Removal of the protecting group (29) followed by reduction of the ketone affords cimaterol (30) 5J. 

Another useful aniline derivative is acetanilide, which is simply the amide formed from aniline and acetic arid ... 

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