Dichlorotoluenes are organochlorine compounds, in particular aryl chlorides, with the formula CH3C6H3Cl2. Six constitutional isomers exist, differing in the relative position of the two chlorine substituents around the ring. They are all colorless and lipophilic. The 3,5 isomer is a solid at room temperature, whereas the others are liquids.
Isomer | 2,3-Dichlorotoluene | 2,4-Dichlorotoluene | 2,5-Dichlorotoluene | 2,6-Dichlorotoluene | 3,4-Dichlorotoluene | 3,5-Dichlorotoluene |
---|---|---|---|---|---|---|
CAS Registry Number | [32768-54-0] | [95-73-8] | [19398-61-9] | [118-69-4] | [95-75-0] | [25186-47-4] |
Density (g/mL) | 1.266, liquid | 1.25, liquid | 1.254, liquid | 1.266, liquid | 1.25, liquid | solid |
Melting pt (°C) | 5 | -13 | 3.2 | 2.6 | -14.7 | 25.1 |
Boiling pt (°C) | 208.1 | 201 | 201 | 201 | 209 | 202 |
Several dichlorotoluenes are prepared by treatment of toluene or monochlorotoluenes with chlorine in the presence of various Lewis acids. Purification is challenging because the individual isomers have similar properties. The 2,6 and 3,5 isomers do not form acceptably from toluene or chlorotoluenes, so these isomers are prepared by indirect methods. For example, 2,6-dichlorotoluene can be prepared by chlorination of 4-toluenesulfonyl chloride followed by desulfonation. [1]
Some dichlorotoluenes are precursors to commercial pesticides. 2,4-Dichlorotoluene is the precursor to pyrifenox, butafenacil, and the pyrazole derivatives pyrazoxyfen and [pyrazolynate]]. The 2,6 isomer is a precursor to dichlobenil (2,6-dichlorobenzonitrile). 3,5-Dichlorotoluene is used to prepare propyzamide. [2]
In organic chemistry, an aryl halide is an aromatic compound in which one or more hydrogen atoms, directly bonded to an aromatic ring are replaced by a halide. Haloarenes are different from haloalkanes because they exhibit many differences in methods of preparation and properties. The most important members are the aryl chlorides, but the class of compounds is so broad that there are many derivatives and applications.
Chlorobenzene (abbreviated PhCl) is an aryl chloride and the simplest of the chlorobenzenes, consisting of a benzene ring substituted with one chlorine atom. Its chemical formula is C6H5Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals.
Benzyl chloride, or α-chlorotoluene, is an organic compound with the formula C6H5CH2Cl. This colorless liquid is a reactive organochlorine compound that is a widely used chemical building block.
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.
Xylenols are organic compounds with the formula (CH3)2C6H3OH. They are volatile colorless solids or oily liquids. They are derivatives of phenol with two methyl groups at various positions relative to the hydroxyl group. Six isomers exist, of which 2,6-xylenol with both methyl groups in an ortho position with respect to the hydroxyl group is the most important. The name xylenol is a portmanteau of the words xylene and phenol.
A chlorophenol is any organochloride of phenol that contains one or more covalently bonded chlorine atoms. There are five basic types of chlorophenols and 19 different chlorophenols in total when positional isomerism is taken into account. Chlorophenols are produced by electrophilic halogenation of phenol with chlorine.
Benzal chloride is an organic compound with the formula C6H5CHCl2. This colourless liquid is a lachrymator and is used as a building block in organic synthesis.
1,2,4-Trichlorobenzene is an organochlorine compound, one of three isomers of trichlorobenzene. It is a derivative of benzene with three chloride substituents. It is a colorless liquid used as a solvent for a variety of compounds and materials.
Durene, or 1,2,4,5-tetramethylbenzene, is an organic compound with the formula C6H2(CH3)4. It is a colourless solid with a sweet odor. The compound is classified as an alkylbenzene. It is one of three isomers of tetramethylbenzene, the other two being prehnitene (1,2,3,4-tetramethylbenzene) and isodurene (1,2,3,5-tetramethylbenzene). Durene has an unusually high melting point (79.2 °C), reflecting its high molecular symmetry.
Hexachlorobutadiene, (often abbreviated as "HCBD") Cl2C=C(Cl)C(Cl)=CCl2, is a colorless liquid at room temperature that has an odor similar to that of turpentine. It is a chlorinated aliphatic diene with niche applications but is most commonly used as a solvent for other chlorine-containing compounds. Structurally, it has a 1,3-butadiene core, but fully substituted with chlorine atoms.
Dichlorophenols (DCPs) are any of several chemical compounds which are derivatives of phenol containing two chlorine atoms. There are six isomers:
2,6-Dichlorophenol is a compound with formula C6H3Cl2OH. It is one of the six isomers of dichlorophenol. It is a colorless solid. Its pKa is 6.78, which is about 100x more acidic than 2-chlorophenol (8.52) and 1000x more acidic than phenol itself (9.95).
2-Chloropyridine is an aryl chloride with the formula C5H4ClN. It is a colorless liquid that is mainly used to generate fungicides and insecticides in industry. It also serves to generate antihistamines and antiarrythymics for pharmaceutical purposes. It is one of three isomers of chloropyridine.
1,3,5-Trichlorobenzene is an organochlorine compound. It is one of the three isomers of trichlorobenzene. Being more symmetrical than the other isomers, it exists as colourless crystals whereas the other isomers are liquids at room temperature.
2-Nitrotoluene or ortho-nitrotoluene is an organic compound with the formula CH3C6H4NO2. It is pale yellow liquid that crystallizes in two forms, called α (−9.27 °C) and β (−3.17 °C). It is mainly a precursor to o-toluidine, which is an intermediate in the production of various dyes.
1,3-Dichlorobenzene (also known as meta-dichlorobenzene) is an aryl chloride and isomer of dichlorobenzene with the formula C6H4Cl2. It is the least common of the three isomers of dichlorobenzene, and it is a colorless liquid that is insoluble in water. It is produced as a minor byproduct of the chlorination of benzene, but can also be prepared in a directed manner by the Sandmeyer reaction of 3-chloroaniline. It also arises from the isomerization of the other dichlorobenzenes at high temperature.
Trichlorotoluenes are organochlorine compounds, in particular aryl chlorides, with the formula CH3C6H2Cl3. Six constitutional isomers exist, differing in the relative position of the three chlorine substituents around the ring. All isomers colorless and lipophilic solids.
4-Chlorophenol is an organic compound with the formula C6H4ClOH. It is one of three monochlorophenol isomers. It is a colorless or white solid that melts easily and exhibits significant solubility in water. Its pKa is 9.14.
1,8-Naphthalic anhydride is an organic compound with the formula C10H6(C2O3). It is one of three isomers of naphthalic anhydride, the other two being the 1,2- and the 2,3-derivatives. The 1,8-isomer is prepared by aerobic oxidation of acenaphthene. 2,6-naphthalenedicarboxylic acid can be prepared from this anhydride. 1,8-Naphthalic anhydride is a precursor to the 4-chloro and 4,5-dichloro derivatives. These chloride groups are susceptible to displacement by amines and alkoxides, giving rise, ultimately, to a large family of naphthalimides, which are used as optical brighteners.
2,6-Dichloro-4-nitroaniline is an organic compound with the formula O2NC6H2Cl2NH2. It is the most widely discussed isomer of dichloronitroaniline, mainly as a precursor to the azo dye disperse brown 1. It is prepared by treatment of 4-nitroaniline with a mixture of hydrochloric acid and hydrogen peroxide.