Triphenylmethane, reaction with

The mechanism of reaction with steroids has not been elucidated. Various nonquantitative reactions occur simultaneously. Cyclopentenyl cations have been postulated as intermediates which condense with anisaldehyde to yield colored compounds [4]. It is probable that triphenylmethane dyes are also formed with aromatic compounds. 

Presumably the active chlorine of the chloramines formed by reaction with chlorine gas or hypochlorite reacts with TDM in the presence of acetic acid to yield dark blue, mesomerically stabilized quinoid reaction products that possibly rearrange to yield triphenylmethane dyestuffs. 

All three chlorine atoms of chloroform take part in the Friedel-Crafts reaction the product of the reaction with benzene is the important hydrocarbon triphenylmethane, the parent substance of the well-known class of dyes. Paraleucaniline, [(p) NH2.C6H4]3CH, has been converted into triphenylmethane by reductive hydrolysis of its tris-diazo-com-pound (E. and 0. Fischer). 

Hirschler and Hudson (36/6), however, favor the opinion that Bronsted sites are exclusively responsible for the activity of silica-alumina. In studying the adsorption of perylene and of triphenylmethane, they concluded that carbonium ions are not formed by a hydride abstraction mechanism as claimed by Leftin (362). Instead, triphenylmethane is oxidized by chemisorbed oxygen to triphenylcarbinol in a photo-catalyzed reaction, followed by reaction with a Bronsted acid giving water and a triphenylmethyl carbonium ion. After treatment with anhydrous ammonia, the organic compound was recovered by extraction as triphenylcarbinol. About thirteen molecules of ammonia per assumed Lewis site were required to poison the chemisorption of trityl ions. The authors explain the selective inhibition of certain catalyzed reactions by alkali by assuming that only certain of the acidic protons will ion-exchange with alkali ions. 

Arenes can also be cleaved with peroxyacetic acid831 and permanganate.636,832 Ru04 effectively oxidizes arenes to cleavage products with the use of a cooxidant such as NaT04. Violent reaction with benzene and immediate oxidation of several other aromatics such as triphenylmethane and tetralin834 take place, but oxidation products could not be isolated. Since alkanes are resistant to Ru04,... 

Rhodamines. Rhodamines are commercially the most important aminoxanthenes. If phthalic anhydride is used in place of formaldehyde in the above condensation reaction with m-diall laminophenol, a triphenylmethane analogue, 9-phenylxanthene, is produced. Historically, these have been called rhodamines. Rhodamine B (Basic Violet 10, Cl45170) (17) is usually manufactured by the condensation of two moles of / -diethylaminophenol with phthalic anhydride (24). An alternative route is the reaction of diethylamine with fluorescein dichloride [630-88-6] (3,6-dichlorofluoran) (18) under pressure. 

The amide ions are powerful bases and may be used (i) to dehydrohalogenate halo-compounds to alkenes and alkynes, and (ii) to generate reactive anions from terminal acetylenes, and compounds having reactive a-hydrogens (e.g. carbonyl compounds, nitriles, 2-alkylpyridines, etc.) these anions may then be used in a variety of synthetic procedures, e.g. alkylations, reactions with carbonyl components, etc. A further use of the metal amides in liquid ammonia is the formation of other important bases such as sodium triphenylmethide (from sodamide and triphenylmethane). 

Benzotrichloride Method. The central carbon atom of the dye is supplied by the trichloromethyl group fromy>-chlorobenzotrichloride. Both symmetrical and unsymmetrical triphenylmethane dyes suitable for acrylic fibers are prepared by this method. 4-Chlorobenzotrichloride is condensed with excess chlorobenzene in the presence of a Lewis acid such as aluminium chloride to produce the intermediate aluminium chloride complex of 4,4, 4"-trichlorotriphenylmethyl chloride (18). Stepwise nucleophilic substitution of the chlorine atoms of this intermediate is achieved by successive reactions with different a.rylamines to give both symmetrical (51) and unsymmetrical dyes (52), eg, N-(2-chlorophenyl)-4-[(4-chlorophenyl) [4-[(3-methylphenyl)imino]-2,5-cyclohexadien-l-yhdene]methyl]benzenaminemonohydrochloride [85356-86-1] (19) from / -toluidine and a-chloroaniline. 

The triphenylmethyl cation reacts with the THF to form triphenylmethane and a protonic acid. We believe that this acid is the true initiator and that its reaction with THF may be slow. This can account in part for the deviations in DP. As Bawn and co-workers pointed out, in the case of the SbCl6 gegenion transfer reactions are probably also important and result in low DP s. 

Stopped flow and continuous flow methods [11] have been used to follow proton transfer reactions with half-lives in the millisecond range. The stopped flow method which is more popular is essentially a device for mixing the reactants rapidly (typically in one millisecond) together with some means of observing the fast reaction which follows. Proton transfer from p-nitrobenzyl cyanide to ethoxide ion in ethanol/ether mixtures at —77 °C was studied in this way [12]. The reaction was followed spectrophotometrically. The most rapid reaction occurred with ti/2 ca. 2 x 10 2 sec although the equipment was suitable for following reactions with f1/2 ca. 2 x 10 3 sec. A similar method has been used to measure rates of proton transfer between weak carbon acids (for example, triphenylmethane) and bases (for example, alkoxide ions) in dimethyl sulphoxide [13], A continuous flow apparatus with spectrophotometric detection was used [14] to measure rates of ionization for substituted azulenes in aqueous solution (4), reactions for which half-lives between 2 and 70 msec were observed. 

The triphenylmethyl carbanion, the trityl anion, can be generated by the reaction of triphenylmethane with the very powerful base, n-butyllithium. The reaction generates the blood-red lithium triphenylmethide and butane. The triphenylmethyl anion reacts much as a Grignard reagent does. In the present experiment it reacts with carbon dioxide to give triphenylacetic acid after acidification. Avoid an excess of n-butyllithium on reaction with carbon dioxide, it gives the vile-smelling pentanoic acid. 

The RjZn compounds react with acidic hydrocarbons to split the original Zn— C bonds and form new ones. The rate depends on hydrocarbon acidity e.g., reactions with triphenylmethane proceed slowly and incompletely. Therefore, it is nearly impossible to obtain organozincs with stoichiometric compositions. More definite results are obtained with 1-alkynes, in which, depending on the molar ratio, one or two organic groups at Zn can be substituted for alkynyl groups ... 

Tomboulian and Stehower5 prepared this reagent in quantitative yield by metala-tion of triphenylmethane with n-butyllithium (50-150% excess) in THF or tetra-hydro-2-methylfurane as solvent. They recommend that the n-butyllithium be prepared from lithium and n-butyl chloride in the reaction solvent. If the exchange is carried out at room temperature, excess butyllithium is rapidly consumed by reaction with tetrahydrofurane. With tetrahydropyrane as solvent, trityllithium was found to react with benzophenonc to form p-(diphenylmethyl)diphenylhydroxymethyl-benzene ... 

Activation of organolithium compounds [1, 926, before references]. Potassium f-butoxide enhances the reactivity of organolithium compounds. For example, benzene is not metalated by n-butyllithium at room temperature, but if potassium /-butoxide is present phenyllithium is formed in 77% yield as shown by the reaction with carbon dioxide to give benzoic acid. Triphenylmethane. diphenylmethane, and toluene are also rapidly metalated.71... 

In a reaction similar in some respects to those described above, 3,4,5-trimethoxytoluene (22) reacts with paraformaldehyde under acidic conditions to yield a mixture of cyclooligomers 23 with n = 4-13. Calix[4]arenes carrying substituents on the bridge methylene groups (25) have been prepared by the acid-catalyzed reaction of triphenylmethanes 24 with paraformaldehyde and obtained in 18-30% yields. 

Triphenylmethane derivatives can be converted into triphenylmethanol derivatives by various oxidizing agents. Triphenylmethane itself with nitric acid or with chromic acid in glacial acetic acid gives triphenylmethanol, and with lead tetraacetate gives triphenylmethyl acetate. The principal importance of this reaction lies in the technical synthesis of triphenylmethane dyes from their leuco bases, for which purpose very varied oxidants such as arsenic acid, nitrobenzene, nitrous acid, and nitrosylsulfuric acid are used. 

In fact, the earliest application of kinetic methods was to determine trace levels of substances exerting catalytic activity in oxidation-reduction reactions involving multiple electron transfers (1885-trace level V on its catalysis of the oxidation of aniline). For example, the reduced form of many triphenylmethane dyes is colorless , and loses two electrons on oxidation to the dye. The rate of reaction with such oxidants as 104 is relatively slow, but can be catalyzed by trace levels of transition metal ions which involve single electron transfer in their own redox steps. Thus, trace levels of manganese can be determined by the proportionality of the rate of oxidation of leuco-malachite green by iodate at less than micromolar concentrations. Similarly, trace levels of Cu ", < 10 M, can be determined from the catalytic effect on the atmospheric oxidation of ascorbic acid. Such systems can be written as a generalized redox reaction... 

Production of N,N-dimethylaniline in Western Europe in 1985 was around 9,0001. Among the most important compounds based on N,N-dimethylaniline is Michler s ketone, which is used to manufacture triphenylmethane dyes such as Basic Violet 3 (Crystal Violet) or Basic Green 4 (Malachite Green), which is obtainable by reaction with benzaldehyde in a sulfuric acid medium, followed by oxidation. 

Triphenylmethide (19) is formed by the reaction of triphenylmethane (PhaCH) with sodium metal, as seen in Section 22.1. It is an unusual but effective base in this reaction because it is a relatively non-nucleophilic base (see Section 22.3). To explain the reaction with 60 and formation of product 61, a mechanism requires that the base first remove the acidic a-proton on C2 from the ester to form enolate anion 62. As with enolate anions derived from ketones and aldehydes, there are two resonance forms, and the carbanion form (62A) is the more nucleophilic. Therefore, resonance contribution 62A will lead to the... 

Reaction qf organotilhiim compounds with ICJisl H. Triphenylmethane and triphenylgermane differ in their reaction with orgamlithium cmnptjunds frt>m triphenylsilane and triphenylstannane ... 

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