Chlorotoluene
{{Distinguish|Benzyl chloride}}
Chlorotoluenes are aryl chlorides based on toluene in which at least one aromatic hydrogen atom is replaced with a chlorine atom. They have the general formula C7H8–nCln, 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.
| align="center" border="1" cellspacing="0" cellpadding="3" style="margin: 0 0 0 0.5em; background: #FFFFFF; border-collapse: collapse; border-color: #C0C090;"
! {{Chemical datatable header}} align="center" colspan="4" | Monochlorotoluene isomers |
| Common name
| {{no redirect|2-Chlorotoluene|o-chlorotoluene}} | {{no redirect|3-Chlorotoluene|m-chlorotoluene}} | {{no redirect|4-Chlorotoluene|p-chlorotoluene}} |
| Structure
| align="center" | 90px | align="center" | 90px | align="center" | 55px |
| Systematic name
| 1-chloro-2-methylbenzene | 1-chloro-3-methylbenzene | 1-chloro-4-methylbenzene |
| Molecular formula
| align="center" colspan="3" | C7H7Cl (C6H4ClCH3) |
| Molar mass
| align="center" colspan="3" | 126.586 g/mol |
| Appearance
| align="center" colspan="3" | colorless liquid |
| CAS number
| [95-49-8] | [108-41-8] | [106-43-4] |
| {{Chemical datatable header}} align="center" colspan="5" | Properties |
|---|
| Density and phase
| 1.073 g/ml, liquid | 1.072 g/ml, liquid | 1.069 g/ml, liquid |
| Solubility in water
| align="center" colspan="3" | practically insoluble |
| Other solubilities
| align="center" colspan="4" | Soluble in non-polar solvents such as aromatic hydrocarbons |
| Melting point
| −35 °C (−31 °F; 238 K) | −47 °C (−52.6 °F; 226 K) | 7 °C (44.6 °F; 280 K) |
| Boiling point
| 159 °C (318.2 °F; 432 K) | 162 °C (323.6 °F; 435 K) | 162 °C (323.6 °F; 435 K) |
| Magnetic susceptibility
| −81.98·10−6 cm3/mol | −80.07·10−6 cm3/mol | −80.07·10−6 cm3/mol |
Benzyl chloride is an isomer, which has a chlorine substituted for one of the hydrogens of toluene's methyl group, and it is sometimes named α-chlorotoluene.
Preparation
A laboratory route to 2- and 4-chlorotoluene proceeds from 2- and 4-toluidines (i.e. 2- and 4-aminotoluene). These compounds are diazotized followed by treatment with cuprous chloride.{{cite journal |doi=10.15227/orgsyn.003.0033|title=o-Chlorotoluene and p-Chlorotoluene|journal=Organic Syntheses|year=1923|volume=3|page=33|author=C. S. Marvel and S. M. McElvain}} 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.{{Ullmann |doi=10.1002/14356007.o06_o03|title=Chlorinated Benzenes and Other Nucleus-Chlorinated Aromatic Hydrocarbons|year=2011|last1= Beck|first1=Uwe|last2=Löser|first2=Eckhard|isbn=978-3527306732}}
Uses
2- and 4-chlorotoluene are precursors to the corresponding benzyl chloride (ClC6H4CH2Cl), benzaldehyde (ClC6H4CHO), and benzoyl chloride (ClC6H4C(O)Cl). 2- and 4-chlorotoluenes are converted to 2-chlorobenzonitrile and 4-chlorobenzonitrile, respectively.{{Ullmann|doi=10.1002/14356007.a17_363|title=Nitriles|year =2000|last1=Pollak|first1=Peter|last2=Romeder|first2=Gérard|last3=Hagedorn|first3=Ferdinand|last4=Gelbke|first4=Heinz-Peter|isbn=3527306730}} Chlorotoluenes are precursors to dichlorotoluenes.
See also
References
{{Reflist}}
- [https://www.cdc.gov/niosh/npg/npgd0135.html CDC - NIOSH Pocket Guide to Chemical Hazards - o-Chlorotoluene]