Chlorotoluenes are

aryl chloride In organic chemistry, an aryl halide (also known as a haloarene) is an aromatic compound in which one or more hydrogen atoms directly bonded to an aromatic ring are replaced by a halide ion (such as fluorine F''−'', chlorine Cl−1,−3,−5, bro ...

s based on

toluene Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon with the chemical formula , often abbreviated as , where Ph stands for the phenyl group. It is a colorless, water Water is an inorganic compound with the c ...

in which at least one aromatic hydrogen atom is replaced with a

chlorine Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...

atom. They have the general formula C₇H_8–''n''Cl_''n'', where ''n'' = 1–5 is the number of chlorine atoms.

Monochlorotoluene

Monochlorotoluenes are chlorotoluenes containing one chlorine atom. There are three isomers, each with the formula C₇H₇Cl.

Properties

The isomers differ in the location of the chlorine, but have the same chemical formula. All have very similar boiling points, although ''p''-chlorotoluene has a much higher melting point due to a more tightly packed crystal structure.

Benzyl chloride Benzyl chloride, or α-chlorotoluene, is an organic compound with the formula . This colorless liquid is a reactive organochlorine compound that is a widely used chemical building block. Preparation Benzyl chloride is prepared industrially ...

is an isomer, which has a chlorine substituted for one of the hydrogens of

's methyl group, and it is sometimes named α-chlorotoluene.

Preparation

A laboratory route to 2- and 4-chlorotoluene proceeds from 2- and 4-

toluidine There are three isomers of toluidine, which are organic compounds discovered and named by James Sheridan Muspratt and August Wilhelm von Hofmann in 1845. These isomers are O-Toluidine, ''o''-toluidine, ''m''-toluidine, and ''p''-toluidine, with the ...

s (i.e. 2- and 4-aminotoluene). These compounds are diazotized followed by treatment with cuprous chloride. Industrially, the diazonium method is reserved for 3-chlorotoluene. The industrial route to 2- and 4-chlorotoluene entails direct reaction of toluene with chlorine. The more valuable 4-chlorotoluene is separated from 2-chlorotoluene by distillation. Distillation cannot be applied to separating 3-chlorotoluene from 4-chlorotoluene.

Uses

2- and 4-chlorotoluene are precursors to the corresponding

benzyl chloride Benzyl chloride, or α-chlorotoluene, is an organic compound with the formula . This colorless liquid is a reactive organochlorine compound that is a widely used chemical building block. Preparation Benzyl chloride is prepared industrially ...

(ClC₆H₄CH₂Cl),

benzaldehyde Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is among the simplest aromatic aldehydes and one of the most industrially useful. It is a colorless liquid with a characteristic almond-li ...

(ClC₆H₄CHO), and

benzoyl chloride Benzoyl chloride, also known as benzenecarbonyl chloride, is an organochlorine compound with the formula . It is a colourless, fuming liquid with an irritating odour, and consists of a benzene ring () with an acyl chloride () substituent. It is ...

(ClC₆H₄C(O)Cl). 2- and 4-chlorotoluenes are converted to

2-chlorobenzonitrile 2-Chlorobenzonitrile is an organic compound with the formula ClC6H4CN. It is a white solid. The compound, one of three isomers of chlorobenzonitrile, is produced industrially by ammoxidation In organic chemistry, ammoxidation is a process for ...

and

4-chlorobenzonitrile 4-Chlorobenzonitrile is an organic compound with the formula ClC6H4CN. It is a white solid. The compound, one of three isomers of chlorobenzonitrile, is produced industrially by ammoxidation of 4-chlorotoluene. The compound is of commercial int ...

, respectively. Chlorotoluenes are precursors to

dichlorotoluene Dichlorotoluenes are organochlorine compounds, in particular aryl chlorides, with the formula . Six constitutional isomers exist, differing in the relative position of the two chlorine substituents around the ring. They are all colorless and lipop ...

References

{{Reflist
CDC - NIOSH Pocket Guide to Chemical Hazards - o-Chlorotoluene
Chlorobenzene derivatives Toluenes Multiple compounds, tabular

Monochlorotoluene

Properties

Preparation

Uses

See also

References