C-Chlorotoluene

The isomer proportions for the nitration of the chlorotoluenes, to be expected from the additivity principle, have been calculated from the partial rate factors for the nitration of toluene and chlorobenzene and compared with experimental results for nitration with nitric acid at o °C. The calculated values are indicated in brackets beside the experimental values on the following structural formulae. In general, it can be... 

The hydrolysis of p bromotoluene with aqueous sodium hydroxide at 300°C yields m methylphenol and p methylphenol in a 5 4 ratio What is the meta—para ratio for the same reac tion carried out on p chlorotoluene" ... 

Halogen Reactions. Hydrolysis of chlorotoluenes to cresols has been effected by aqueous sodium hydroxide. Both displacement and benzyne formation are involved (27,28). o-Chlorotoluene reacts with sodium in Hquid ammonia to afford a mixture of 67% of o-toluidine [95-53-4] and 33% of yW-toluidine [108-44-1], C H CIN, as shown in equation 3 (29). 

With hydrogen sulfide at 500—600°C, monochlorotoluenes form the corresponding thiophenol derivatives (30). In the presence of palladium catalysts and carbon monoxide, monochlorotoluenes undergo carbonylation at 150—300°C and 0.1—20 MPa (1—200 atm) to give carboxyHc acids (31). Oxidative coupling of -chlorotoluene to form 4,4 -dimethylbiphenyl can be achieved in the presence of an organonickel catalyst, generated in situ, and zinc in dipolar aprotic solvents such as dimethyl acetamide (32,33). An example is shown in equation 4. 

The rate of chlorination of toluene relative to that of ben2ene is about 345 (61). Usually, chlorination is carried out at temperatures below 70°C with the reaction proceeding at a profitable rate even at 0°C. The reaction is exothermic with ca 139 kj (33 kcal) of heat produced per mole of monochlorotoluene formed. Chlorine efficiency is high, and toluene conversion to monochlorotoluene can be carried to about 90% with the formation of only a few percent of dichlorotoluenes. In most catalyst systems, decreasing temperatures favor formation of increasing amounts of -chlorotoluene. Concentrations of requited catalysts are low, generally on the order of several tenths of a percent or less. 

Chlorination of OCT with chlorine at 90°C in the presence of L-type 2eohtes as catalyst reportedly gives a 56% yield of 2,5-dichlorotoluene (79). Pure 2,5-dichlorotoluene is also available from the Sandmeyer reaction on 2-amino-5-chlorotoluene. 3,4-Dichlorotoluene (l,2-dichloro-4-methylben2ene) is formed in up to 40% yield in the chlorination of PCT cataly2ed by metal sulfides or metal halide—sulfur compound cocatalyst systems (80). 

Benzyl chloride [(chloromethyl)henzene, a-chlorotoluene], CgH CH2Cl, is a colorless Hquid with a very pungent odor. Its vapors are irritating to the eyes and mucous membranes, and it is classified as a powerfljl lacrimator. The physical properties of pure benzyl chloride are given in Table 2 (2—7). Benzyl chloride is insoluble in cold water, but decomposes slowly in hot water to benzyl alcohol. It is miscible in all proportions at room temperature with most organic solvents. The flash point of benzyl chloride is 67°C (closed cup) 74°C (open cup) autoignition temperature is 585°C lower flammability limit 1.1% by volume in air. Its volume coefficient of expansion is 9.72 x. ... 

Chemical Designations - Synonyms alpha-Chlorotoluene omega-Chlorotoluene Chlorotoluene, alpha Chemical Formula C HjCHiCl. 

Stock and Baker2 5 9 measured the relative rates of chlorination of a number of halogenated aromatics in acetic acid containing 20.8 M H20 and 1.2 M HC1 at 25 °C and the values of the second-order rate coefficients (103Ar2) are as follows p-xylene (11,450), benzene (4.98), fluorobenzene (3.68), chlorobenzene (0.489), bromobenzene (0.362), 2-chlorotoluene (3.43), 3-chlorotoluene (191), 4-chloro-toluene (2.47), 4-fluorotoluene (9.70), 4-bromotoluene (2.47). Increasing the concentration of the aromatic, however, caused, in some cases, a decrease in the rate coefficients thus an increase in the concentration of chlorobenzene from 0.1 M to 0.2 M caused a 20 % decrease in rate coefficient, whereas with 4-chloro-and 4-bromo-toluene, no such change was observed. 

Relative rates of aluminium chloride-catalysed acetylation of a range of aromatics with acetyl chloride at 0 °C had earlier been measured by McDuffie and Dougherty419 as follows 4-chlorotoluene, 0.0137 bromobenzene, 0.0242 chlorobenzene, 0.0314 2-chlorotoluene, 0.271 benzene, 1.0 toluene, 13.3 mesity-... 

When the two groups in disubstituted benzenes are different, the same three isomers are possible that are possible when the substituents are the same. Compounds with two different substituents are usually named as positional derivatives of a monosubstituted (parent) compound. Above, the common (and commercial) name for methylbenzene is toluene, and the chlorinated derivatives are named as shown above. However, the same two chlorinated derivatives can also be properly named 2-chloromethylbenzene and 4-chloromethylbenzene. In this case, for naming, the parent compound is methylbenzene and it is understood that the methyl group is in the 1-position. The terms ortho- (1,2-), meta- (1,3-), and para- (1,4-) are also sometimes used for example, 2-chlorotoluene can be called ortho-c Aoioio -uene. This can be very confusing, but in the chemical industry, outside of the research labs, the common names for the parent compounds are almost always used. 

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