Nitrobenzene chloronitrobenzene

There is increasing evidence that the ionisation of the organic indicators of the same type, and previously thought to behave similarly, depends to some degree on their specific structures, thereby diminishing the generality of the derived scales of acidity. In the present case, the assumption that nitric acid behaves like organic indicators must be open to doubt. However, the and /fp scales are so different, and the correspondence of the acidity-dependence of nitration with so much better than with Hg, that the effectiveness of the nitronium ion is firmly established. The relationship between rates of nitration and was subsequently shown to hold up to about 82 % sulphuric acid for nitrobenzene, />-chloronitrobenzene, phenyltrimethylammonium ion, and p-tolyltrimethylammonium ion, and for various other compounds. ... 

Table 9.7 contains recent data on the nitration of polychlorobenzenes in sulphuric acid. The data continue the development seen with the diehlorobenzenes. The introduetion of more substituents into these deactivated systems has a smaller effect than predicted. Whereas the -position in ehlorobenzene is four times less reactive than a position in benzene, the remaining position in pentachlorobenzene is about four times more reactive than a position in 1,3,4,5-tetraehlorobenzene. The chloro substituent thus activates nitration, a circumstance recalling the faet that o-chloronitrobenzene is more reactive than nitrobenzene. As can be seen from table 9.7, the additivity prineiple does not work very well with these compounds, underestimating the rate of reaction of pentachlorobenzene by a factor of nearly 250, though the failure is not so marked in the other cases, especially viewed in the circumstance of the wide range of reactivities covered. 

Where does the hydrogen atom in the product of hydro-de-diazoniation, 2-chloro-nitrobenzene (8.66), come from in CH3OD It was found (Bunnett and Takayama, 1968 b Broxton and Bunnett, 1979) that in the reaction of Scheme 8-47 the deuterium content of 2-chloronitrobenzene was 79%, a figure which is not close to either zero or 100%. For other substituted benzenediazonium ions a very wide range of D incorporation was observed. This range is consistent with hydro-de-diazoniation by both homolytic and a competitive anionic mechanism. The anionic pathway is favored by an increase in methoxide ion concentration. 

TRINITROBENZENE m-DIBROMOBENZENE m-CHLORONITROBENZENE o-CHLORONITROBENZENE p-CHLORONITROBENZENE tn-D I CHLOROBENZENE o-DICHLOROBENZENE p-DI CHLOROBENZENE m-DIFLUOROBENZENE o-DIFLUOROBENZENE p-DIFLUOROBENZENE m-DI NITROBENZENE o-DINITROBENZENE p-DINITROBENZENE BROMOBENZENE MONOCHLOROBENZENE m-CHLOROPHENOL o-CHLOROPHENOL p-CHLOROPHENOL... 

The ONSH reaction of the carbanion of 2-phenylpropionitrile (45 c) with nitrobenzene in liquid ammonia at -70 °C involves rate-limiting Carom—H bond breaking, as evidenced by the 9.8 times faster rate than for reaction of the analogous substitution of deuterium in 4-<7-nitrobenzene and perdeuterionitrobenzene. Reactions of the carbanion derived from (45c) with 4-chloro-3-trifluoromethylnitrobenzene and 4-chloronitrobenzene in toluene under phase transfer catalysis has also been studied." ... 

Chloromethyl) oxhane, see Epichlorohydrin 2-(Chloromethyl)oxirane, see Epichlorohydrin 4-Chloro-3-methylphenol, see p-Chloro-ro-cresol p-Chloro-3-methylphenol, see p-Chloro-ro-cresol Chloromethyl phenyl ketone, see a-Chloroacetophenone p-Chloronaphthalene, see 2-Chloronaphthalene 4-Chloronitrobenzene, see p-Chloronitrobenzene l-Chloro-4-nitrobenzene, see p-Chloronitrobenzene 4-Chloro-l-nitrobenzene, seep-Chloronitrobenzene p-Chloro-1-nitrobenzene, see p-Chloronitrobenzene Chloronitroform, see Chloropicrin Chloronitropropane, see 1-Chloro-l-nitropropane Chlorophen, see Pentachlorophenol... 

Nitric acid, see 1-Butene, o-Chloronitrobenzene. p-Chloronitrobenzene, Chloropicrin, 2,3-Dichloronitrobenzene. 3.4-Dichloronitrobenzene. 2,4-Dinitrophenol, Formaldehyde, Isopropylbenzene, Methanol, Methyl mercaptan, 2-Methylphenol, 2-Methylpropene, Methyl sulfide. Nitrobenzene, 2-Nitrophenol, 4-Nitrophenol,... 

As seen from Table 4.2, activation energies of chlorine substitution in nitrochlorobenzenes under the action of diverse nucleophilic reagents are in agreement with a, of anion-radicals. Constants and of 4-chloronitrobenzene anion-radical are close to the and constants of nitrobenzene... 

Dangwal SK, Jethani BM. 1980. Simple method of determination of nitrobenzene and chloronitrobenzene in air and urine. American Industrial Hygiene Association Journal 41 847-850. 

The published research on the photochemical decomposition of di-azonium salts suggests that the two processes, a heterocyclic and a homolytic process, analogous to those of the thermal decomposition may occur. Various workers 36 187 have reported that phenols are formed when diazonium salts are photolyzed in water and aryl ethers result when an alcohol replaces water as the solvent. Homer and Stohr122 report that a process analogous to reductive deamination occurs in preference to ether formation results in alcohols. The importance of free radical intermediates in the photodecomposition, based on magnetic susceptibility measurements, has been stressed.25 Lee and his co-workers171 have recently suggested that in ethanol the photodecomposition of a diazonium salt occurs via a radical intermediate while in water an ionic process predominates. Thus, photodecomposition of a nitrobenzene diazonium chloride in water yielded both a nitrophenol and a chloronitrobenzene in ethanol, on the other hand, the major product of photolysis was the reduction product, nitrobenzene. 

The possibility of using of aliphatic alcohols as hydrogen donors for the catalytic transfer reduction of nitro group over MgO was examined. Catalytic hydrogen transfer was found to be effective and selective method for reduction of nitrobenzene, A-nitrotoluene, A-chloronitrobenzene, 4-nitro-m-xylene, 3-nitro-styrene, 3-nitrobenzaldehyde, 1-nitropropane, and 1-nitrobutane. Conversion of starting nitro compound into desired product depended on the alcohol used as a donor. Adsorption of reactant and catalyst deactivation were studied by esr. New aspects of a role of one-electron donor sites in hydrogen transfer over MgD were demonstrated. 

By-product p-Chloronitrobenzene. (1 -GMoro-4-nitrobenzene) C8H4(C1)(N02)[1 4], C8H402NC1. 157-5. 

More elaborate catalysts have also been used, like tris(3,6-dioxaheptyl)amine (TDA-1) in dechlorinations of chloropyridines by benzyl alcohol160 and of 4-chloronitrobenzene, 4-chlorobenzonitrile, and 2-chloro-5-(trifluoromethyl)nitrobenzene by phenols and methanethiol.161... 

As can be seen from Table 4-2, the relative rates of chlorine substitution in nitrochlorobenzenes under the action of different nucleophilic reagents are in agreement with af of the anion radicals. The constants af and af of the 4-chloronitrobenzene anion radical are close to the af and af constants of the nitrobenzene anion radical. The pair of anion radicals of 2-chloronitrobenzene and nitrobenzene show the same agreement between af and af. In the anion radical of nitrobenzene, af is larger than af. The substitution of ethoxyl for chlorine in 4-chloronitrobenzene proceeds much more easily and requires a lower activation energy than the same substitution in 2-chloronitrobenzene. The spin density in position 4 of the anion radical of 1,3-dinitrobenzene is greater than that in position 2 (af > af). Therefore, l,3-dinitro-4-chlorobenzene is more active in nucleophilic substitution than l,3-dinitro-2-chlorobenzene. 

Chlorination of nitrobenzene would not be a suitable route to the required intermediate, because it would produce mainly m-chloronitrobenzene. 

The above process was applied initially [142,144] to destroy 100 ppm aniline and 4-chloroaniline in alkaline solutions of pH between 11 and 13 by anodic oxidation in the presence of H202 electrogenerated at an ODC (54 mM H202 at 600 mA). Both substrates presented pseudo first-order decays with half-lives less than 30 min at 600 mA. After 11 hr of electrolysis at 300 mA, a TOC decay >95% was found (see Table 4). Nitrobenzene and p-chloronitrobenzene were detected, respectively, as intermediates, which degraded via maleic acid. Cl was quantitatively released from 4-chloroaniline, and NH3 was a final product of both substrates. General reaction pathways involving oxidation of organics by OH and H02 were proposed. 

At 0°C 30.1% of the ortho- and 69.9% of the para- isomer is formed, at 30°C 26.9% of the ortho-, and 73.1% of the para-isomer is formed. Besides, higher temperatures favour the formation of some small quantities of m- chloronitrobenzene. The product is prepared commercially mainly by chlorination of nitrobenzene in the presence of ferric chloride. 

In the reaction of chloronitrobenzene and nitraniline with alkali the halogen atom or the amino group is only mobile in the 0 andp isomers and is replaceable by OH (also by CN, CNS etc.) much more readily than in chlorobenzene or aniline. This is a reaction of the nucleophilic OH- ion. 0-Nitrophenol and some -nitrophenol, but no meta, can indeed be produced from nitrobenzene with alkali also, though with difficulty. 

Use has been made of such considerations Epiotis has accounted for the differential reactivity of chloronitrobenzenes toward nucleophiles in terms of the spin distribution in nitrobenzene anion-radicals he has also correlated the reactivity of anisole and benzoate esters toward nucleophilic radicals... 

About 40 grams of liquid boih ng at 85-106° at 9 mm. This fraction consists of nitrobenzene and some chloronitrobenzene. 

The yield of m-chloronitrobenzene is about 60 per cent, or 75 per cent allowing for the recovered nitrobenzene. The pure product boils at 107° at 9 mm. and melts at 44.5°C. 

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