Aniline-based derivatives

Ferrocene-containing sulfur ligands have been used in complex formation with zinc. 3-Ferro-cenyl-3-mercaptopropenale and l,l -bis(3-mercaptopropenale)ferrocene (112) form stable complexes as do their Schiff base derivatives with aniline or 1,2-ethylenediamine. The Fen/Fein redox couple shows only minor metal dependence, this is attributed to tetrahedral distortion.884... 

Symmetrical, aniline-based, and aromatic oxo-squaraines are synthesized via a one-step reaction by heating two equivalents of the appropriate /V,/V-dialkylaniline or other reactive aromatic or heteroaromatic derivatives with squaric acid (Fig. 6) [38, 41]. Unsymmetrical aniline-type squaraines can be synthesized in two steps first one component is reacted with squaric acid dichloride to yield a mono-squaraine intermediate, which in a subsequent step is then reacted with the second component to yield the unsymmetrical squaraine dye [53]. 

Finally, it remains to be mentioned at this point that the protonation of Schiff base derivatives of p-aminoazobenzene has also been studied (Ricketts and Cho, 1961). Benzylidene-j -phenylazo-aniline [54] and its jt>-dimethylamino-derivative in mild acid solution show absorption bands at both 320 nm and 500 nm. These bands are... 

Very reeently Kureshy et al. [98] further reported non-salen chiral Schiff base derived Ti complexes as eatalysts 70, 71 (Figure 23) in the KR of meso-siiXheae oxide, cyclohexene oxide, cyelooetene oxide and cA-butene oxide with anilines. The study deliberated upon the role of several ehiral and achiral additives with these catalysts to give chiral y9-amino alcohols with high enantioselectivity ee, >99%) in excellent yield (>99%) at 0 °C in lOh. Unlike the monomerie version 72 the chiral catalyst 70 used in this study was recoverable and recyclable several times with retention of its performance (Table 10)... 

Schiff bases derived from salicylaldehyde and aniline and its derivatives 941... 

The structure and properties of [Fe (H20)6][Fe (tsb)2]2 2H20, where tsb = the terdentate Schiff base derived from salicylideneglycine, have been described. The detailed 2D structures of salts of [ Fe(saleiA 2 Fe(CN) 6] depend on the nature of the cation and the solvent used in their preparation. Binuclear iron(III) complexes have been prepared from Schiff bases derived from 2,6-diformyl-p-cresol and anilines. 

It turned out that only the compounds listed on the right side of the scheme, namely those containing one nitrogen atom, are reduced to the aniline base by fermenting yeast no distinct reduction of the azo derivatives was observed. Whether this would be possible by altering the experimental conditions cannot be stated offhand (see p. 100). 

Trapping 393 with a Schiff base derived from aniline gave an A-phenylaziridine 400. " Deprotonation of 400 followed by quenching with an electrophile produced the tetrasubstituted-A-phenylaziridine 401, analogous to the conversion of 395 to 398. ... 

In contrast, some substituted anilines, e.g. 2-nitroaniline,143 2-chIoro-4-(trifluoromethyI)ani-Iine,143 benzene-1,3-diamine,150 or 4-chlorobenzene-1,3-diamine,150 give only very low yields of product or formed tars under the fluorination conditions. The diazotization followed by in situ fluorodediazoniation of the corresponding diazonium salts have been systematically studied in hydrogen fluoridc/base solutions of different composition to ascertain the most important influences on the reaction.329 Besides numerous examples of substituted anilines, various derivatives of pyridine, pyrimidine, 1.3,5-triazine, and benzthiazole have been included in these investigations (yields 45—99%). 

An interesting variation in reactivity has also been shown20 in the carbocyclic series on reaction of Schiff s base derived from aniline and p-chlorobenzaldehyde with a number of isomeric dichlorotoluenes. 2,4-Dichlorotoluene yields only the expected stilbene 2,5-dichloro-toluene, according to reaction conditions and molar ratios, gives either the stilbene or 1,2,3-triarylpropane, whereas 2,6-dichlorotoluene yields only the addition product 24. 

In Table I and in Tables II,V,VII,IX,X,XII,XVI, the general formula 29 represents the product resulting from condensation of a methyl component (M-CH3) with a Schiff s base derived from an aldehyde (A-CHO) and an aniline. 

It was also established that Schiff s bases derived from />-chloro-aniline are especially reactive toward 2-(p-tolyl)naphtho[l,2-6 ]triazole.68... 

Schiff bases, derived from 2-(2,3-dihydropyran)carboxaldehyde and anilines, add diazomethane to give triazoline adducts in yields ranging from 45 to 66%.349... 

Crounse and Desai29 showed further that 2-(/>-tolyl)benzo[6]furan with Schiff s base derived from terephthalaldehydic acid and aniline gives, on treatment with excess potassium r-butoxide, the corresponding stilbene carboxylic acid. Schiff s base derived from phthalaldehydic acid and aniline exists30 as the 3-anilinophthalide (40). Nevertheless, this also reacts similarly with, for example, the naphthofuran (39) to form 2-(2 -carboxystilben-4-yl)naphtho [ 1,2-6]furan (41).29 Analogous car-... 

Photochromlsm has been observed in salicylidene aniline, in many of its derivatives and Schlff s bases derived from other orthohydroxy aldehydes (45). This has been Investigated extensively by Cohen, Hlrschberg, and Schmidt (5,47-50,42). 

References for articles reporting results of ab initio quantum chemical calculations on different properties of aniline and derivatives can be retrieved from the compilation Quantum Chemistry Library Data Base (QCLDB), Japan Association for International Chemical Information, Tokyo, Japan, 2005. 

It should be noted that the keto-enamine tautomers of Schiff bases are observed always when the latter are derived from 2-hydroxynaphthaldehyde and aniline. However, in Schiff bases derived from salicylaldehyde and aniline, the new band at >400 nm in UV-Vis spectra was not observed in both polar and non-polar solvents, but it appeared in acidic media. In this workl which contains a quite good survey of the investigations of tautomerism in Schiff bases, the effects of the solvent polarity and acidic media on the phenol-imine keto-amine tautomeric equilibrium in systems 55 and 56 were reported. It was shown by H NMR and UV-Vis spectra that compound 55 is in tautomeric equilibrium of structures 55a and 55b in both polar and non-polar solvents (equation 17), whereas the tautomer 56b was not observed for compound 56 (equation 18) . ... 

Saponin ia a base derived from commercial oils, rich in the superior bomologues of aniline (toluidines). Its hydrochloratc is used in place of saffiower. 

TiX4,n(3-cyanopyridine) (X = Cl or Br and n = 1 or 2) complexes have been prepared from their constituent molecules by mixing in a chlorinated hydrocarbon solvent. I.r. spectra suggest that, for the n = 2 complexes, the ligands are co-ordinated via the pyridine nitrogen only, but that when n — 1 the cyano-nitrogen is also involved. The complexes TiCl4L2 have been characterized, where L is a unidentate, aromatic Schiff base derived from benzaldehyde, anisaldehyde, or salicylaldehyde and amines such as aniline, 0-, m-, or p-toluidine or other substituted anilines. The electronic and i.r. spectra of these complexes are consistent with octahedral stereochemistry... 

In addition, Schiff bases can also be applied as intermediates of quinoline formation. Thus, Schiff bases derived from 2-(trifluoromethyl) aniline and a methyl naphthone, mediated by lithium 2-(dimethylamino)-ethylamide, were used to furnish a series of substituted 2-(2-naphthyl)quinolines designed to target DNA. ... 

The intermediate labile iminium salt was isolated as its chloride in a gas-solid reaction between 2 and HCL Water vapor produced 3 and aniline after final neutralization. Racemic Troger s base derivatives can be optically resolved by chromatography at chiral stationary phases. Absolute configurations of Troger s bases 1 were determined and recently corrected (—) (R,R)-1 ... 

Kemia have disclosed a series of bis-aniline urea-based derivatives of the Pfizer tropane series induding 31 which showed good antiviral activity HIV-1 (EC90 6nM) and encouraging pharmacokinetics in the rat P 52%, To.s 7.2 h) [126]. 

As other double bonded chromophores, the imine chromophore is liable to photochemical E/Z isomerization. The problem has been examined in detail for N-benzylidene aniline and derivatives for both the experimental and computational (TD DFT) point of view. This has given a detailed picture of the effect of substituents on the various steps involved and thus has allowed to predict the best choice of molecules that work as optimal switches , that is are characterized by a well apparent photochromic effect, while maintaining a reasonable thermal stability.High level ab initio calculations have been devoted to the analysis of the isomerization of tZt-penta-3,5-dieniminium cation, a simplified model for the protonated Schiff base of W-cis retinal in rhodopsin. ... 

As there are 90 chloride or nitrous derivatives of benzene, the question which preoccupied Landsteiner and Jacobs (1935) was that of knowing if they were all sensitizing. Some of these derivatives form in vitro a substitution compound with an organic base, aniline whereas the other derivatives do not react with aniline. The derivatives which react are the ones capable of sensitizing guinea pigs. This was confirmed in man by Sulzberger and Baer (1938). 

Mattes, B.R. Wang, H.L. Yang, D. Zhu, Y.T. Blumenthal, W. R. Himdley, M.F. Formation of conductive poly aniline fibers derived from highly concentrated emeraldine base solutions. Synt. Met., 84 (1994), pp. 45-49... 

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