Amination chlorobenzene

Synonyms 2-Amino-5-chlorotoluene 3-chloro-6-aminotoluene 5-chloro-2-amino-toluene 4-chloro-2-methylaniline 4-chloro-6-methylaniline 4-chloro-2-toluidine / ara-chloro-ort/ro-toluidine 2-methyl-4-chloroaniline 2-methyl-4-chlorobenzene-amine... 

Titrations with dibutylamine [111-92-2] can also be used to determine the NCO content of isocyanates and prepolymers. Generally, an excess of amine in a suitable solvent such as chlorobenzene [108-90-7] is added to the sample. The resulting solution is allowed to react and the unreacted amine is back- titrated with dilute hydrochloric acid. For low NCO content levels, a colorimetric method is often used. The isocyanate-containing species is titrated with amine and the unreacted amine is deterrnined using malachite green [569-64-2]. 

PMMA is not affected by most inorganic solutions, mineral oils, animal oils, low concentrations of alcohols paraffins, olefins, amines, alkyl monohahdes and ahphatic hydrocarbons and higher esters, ie, >10 carbon atoms. However, PMMA is attacked by lower esters, eg, ethyl acetate, isopropyl acetate aromatic hydrocarbons, eg, benzene, toluene, xylene phenols, eg, cresol, carboHc acid aryl hahdes, eg, chlorobenzene, bromobenzene ahphatic acids, eg, butyric acid, acetic acid alkyl polyhaHdes, eg, ethylene dichloride, methylene chloride high concentrations of alcohols, eg, methanol, ethanol 2-propanol and high concentrations of alkahes and oxidizing agents. 

Solubility. One of PVP s more outstanding attributes is its solubility in both water and a variety of organic solvents. PVP is soluble in alcohols, acids, ethyl lactate, chlorinated hydrocarbons, amines, glycols, lactams, and nitroparaffins. SolubiUty means a minimum of 10 wt % PVP dissolves at room temperature (moisture content of PVP can influence solubiUty). PVP is insoluble in hydrocarbons, ethers, ethyl acetate, j -butyl-4-acetate, 2-butanone, acetone, cyclohexanone, and chlorobenzene. Both solvent polarity and H-bonding strongly influence solubiUty (77). 

Evidence for symmetrical intermediates such as benzyne cannot be established by quantitative analysis of the reaction mixture unless a labelled starting substance is used. By applying labeling techniques, Roberts and his collaborators obtained results which indicated that benzyne (13) occurs as an intermediate in the amination of chlorobenzene with potassium amide in liquid ammonia. From chlorobenzene-1-C (12) about equal amounts of anUine-l-C (14) and aniline-2-C (15) were formed. More or less probable alternative... 

Beside metal salts, a variety of other modifiers, which include amines, chlorobenzene, hydroxides (S2,S2a), and sulfur compounds, have been used. Among amines used are quinoline (SJ0J7,S4), pyridine (29,33,50,60,64), piperidine, aniline, and diethylaniline. The reduction may be quite sensitive to these modifiers for instance, one drop of quinoline was sufficient to cause hydrogenation to come to an abrupt stop after absorption of I mol of hydrogen (2a). 

More than twenty years ago, Nesmeyanov s group showed that chlorine can be substituted by a variety of nucleophiles in FeCp(r 6-PhCl)+ [83, 84]. Indeed the chlorine substituent in the chlorobenzene (even) ligand is 1000 times more reactive than when it is located on the cyclopentadienyl (odd) ligand [85]. The FeCp+ is a good withdrawing group which is equivalent to two nitro groups in terms of activation. The reactions proceed under ambient conditions with primary or secondary amines and have been extended to other substituted chloroarene complexes [86, 87] Eq. (22), Table 2. 

Various Cu-exchanged zeolites have been examined in the nucleophilic substitution of bromo- and chlorobenzene towards aminated and oxygenated compounds (ref. 30). In amination a consecutive reaction to diphenylamine and reduction to benzene are the side-reactions (Fig. 10). 

Spray solution II For aromatic amines Dissolve 200 mg p-chloranil in 100 ml chlorobenzene [1]. 

Note It is reported that the use of chlorobenzene as solvent is essential when the reagent is to be used to detect aromatic amines [1]. In the case of steroids, penicillins, diuretics and alkaloids the reaction should be accelerated and intensified by spraying afterwards with dimethylsulfoxide (DMSO) or dimethylformamide (DMF), indeed this step makes it possible to detect some substances when this would not otherwise be possible [5,9-11] this latter treatment can, like heating, cause color changes [5,9]. Penicillins and diuretics only exhibit weak reactions if not treated afterwards with DMF [10, 11]. Steroids alone also yield colored derivatives with DMSO [9]. Tlreatment afterwards with diluted sulfuric acid (c = 2 mol/L) also leads to an improvement in detection sensitivity in the case of a range of alkaloids. In the case of pyrrolizidine alkaloids it is possible to use o-chloranil as an alternative detection reagent however, in this case it is recommended that the plate be treated afterwards with a solution of 2 g 4-(dimethyl-amino)-benzaldehyde and 2 ml boron trifluoride etherate in 100 ml anhydrous ethanol because otherwise the colors initially produced with o-chloranil rapidly fade [12]. 

A study of the reaction of chlorobenzene with /V-mclhyl aniline in the presence of Pd[P(r-Bu)3]2 and several different bases indicated that two mechanisms may occur concurrently, with their relative importance depending on the base, as indicated in the catalytic cycle below. The cycle on the right depicts oxidative addition followed by ligation by the deprotonated amine. The cycle on the left suggests that oxidative addition occurs on an anionic adduct of the catalyst and the base, followed by exchange with the amine ligand.167... 

Other poisons (modifiers) used to create such selective Pd catalysts may be metals 23 Zn, Cd, Zr, Ru, Au, Cu, Fe, Hg, Ag, Pb, Sb, and Sn or solvents (organic modifiers) 24 pyridine, quinoline, piperidine, aniline, diethylamine, other amines, chlorobenzene, and sulfur compounds. Hydroxides have also been used to increase the half-hydrogenation selectivity of Pd. 

Products derived from intermediate zwitter-ions have been obtained in the reactions of benzynes with tertiary amines 1>. Benzyne generated by the reaction of -butyl-lithium with fluorobenzene interacts with AT.Af-dimethylaniline to yield iV-methyl diphenylamine and AT-ethyl diphenylamine 132,133). Using the reaction of chlorobenzene with n-butyl-lithium to generate benzyne resulted in the formation of increased amounts of 2-A7,AT-dimethylaminobiphenyl 132,133)... 

Vardanyan [65,66] discovered the phenomenon of CL in the reaction of peroxyl radicals with the aminyl radical. In the process of liquid-phase oxidation, CL results from the disproportionation reactions of primary and secondary peroxyl radicals, giving rise to trip-let-excited carbonyl compounds (see Chapter 2). The addition of an inhibitor reduces the concentration of peroxyl radicals and, hence, the rate of R02 disproportionation and the intensity of CL. As the inhibitor is consumed in the oxidized hydrocarbon the initial level of CL is recovered. On the other hand, the addition of primary and secondary aromatic amines to chlorobenzene containing some amounts of alcohols, esters, ethers, or water enhances the CL by 1.5 to 7 times [66]. This effect is probably due to the reaction of peroxyl radicals with the aminyl radical, since the addition of phenol to the reaction mixture under these conditions must extinguish CL. Indeed, the fast exchange reaction... 

Hydroperoxides oxidize aromatic amines more readily than analogous phenols. Thus, at 368 K cumyl hydroperoxide oxidizes a-naphthylamine and a-naphthol with ku = 1.4 x 10 4 and 1.7 x 10 5L mol-1 s 1, respectively [115,118], The oxidation of amines with hydroperoxides occurs apparently by chain mechanism, since the step of free radical generation proceeds much more slowly. This was proved in experiments on amines oxidation by cumyl hydroperoxide in the presence of /V,/V -diphcnyl-l, 4-phcnylcnediamine (QH2) as a radical acceptor [125]. The following reactions were supposed to occur in solution (80% decane and 20% chlorobenzene) ... 

In addition to peroxyl radicals and hydroperoxide, amines are oxidized by dioxygen and this reaction was found to be catalyzed by the copper surface also. This reaction was studied in chlorobenzene and occurs with the rate ... 

We know that nuclear halogens can be replaced by amine groups but with difficulty. Yet aniline has been manufactured from chlorobenzene by heating it with excess aqueous ammonia in presence of Cu20 at about 250° under pressure. 

Route B of this process may be substantially improved in terms of yield and product quality (purity) of the resulting triarylaminoarylcarbonium pigment. To this end, the solution of the free dye base is treated with an excess of aqueous sulfuric acid (20 to 40% ) in a solvent such as chlorobenzene or an aromatic amine. This method produces the sulfate of the basic dye, which is insoluble in this medium, together with the soluble sulfates of the primary aromatic amines, which can therefore easily be separated. The isolated sulfate of the basic dye is then washed and in dry or wet condition monosulfonated with 85 to 100% sulfuric acid. Based on the dye base sulfate, this step affords 96 to 98% yield, compared to only 83 to 89% achieved by the previously described method. The entire synthesis, including the intermediate isolation of the triarylaminoarylmethane sulfate, may also be performed by continuous process [3]. 

Zhang developed a monolithic poly(styrene-co-divinylbenzene) CEC column in which the EOF is supported by carboxyl groups of polymerized methacrylic acid [ 133]. Using benzene as a probe, column efficiencies of 90,000 -150,000 were observed within a flow velocity range of l-10cm/min (0.2-1.7 mm/s). Different families of compounds such as phenols, anilines, chlorobenzenes, phenylendi-amines, and alkylbenzenes were well separated typically in less than 5 min using 20 cm long columns. 

In this way, the concept of donicity explains some properties of substances usually defined apolar from their usual parameters of polarity (dielectric constant, dipolar moment, Et parameter value) but which presents high possibilities of interaction (and of solvatation) with positively charged centres. This is the case of tertiary amines such as triethylamine (or of ethers such as THF, dioxane) which shows usual polarity parameters near that of apolar solvents (benzene, chloroform, chlorobenzene, 1,2-dichloroethane, etc.) but high ability to coordinate positive charges. 

Additionally, dimedone derivative 241 and propargylamine 234 could be combined to give the alkynyl vinyl amine 242. The rearrangement/cyclization cascade could be induced upon heating until reflux in chlorobenzene. The an-... 

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