Product Code Database
| Two representations of chloroform. |
Organochlorides such as trichloroethylene, tetrachloroethylene, dichloromethane and chloroform are commonly used as solvents and are referred to as "chlorinated solvents".
Aliphatic organochlorides are often as chlorine can act as a leaving group, which can result in cellular damage.
The natural organochloride epibatidine, an alkaloid isolated from tree frogs, has potent analgesic effects and has stimulated research into new pain medication. However, because of its unacceptable therapeutic index, it is no longer a subject of research for potential therapeutic uses. The frogs obtain epibatidine through their diet which is then sequestered into their skin. Likely dietary sources are beetles, ants, mites, and flies.
The haloform reaction, using chlorine and sodium hydroxide, is also able to generate alkyl halides from methyl ketones, and related compounds. Chloroform was formerly produced thus.
Chlorine adds to the multiple bonds on alkenes and alkynes as well, giving di- or tetra-chloro compounds.
In oxychlorination, hydrogen chloride instead of the more expensive chlorine is used for the same purpose:
Secondary and tertiary alcohols react with hydrogen chloride to give the corresponding chlorides. In the laboratory, the related reaction involving zinc chloride in concentrated hydrochloric acid:
In the laboratory, thionyl chloride is especially convenient, because the byproducts are gaseous. Alternatively, the Appel reaction can be used:
Heating alkyl halides with sodium hydroxide or water gives alcohols. Reaction with or give in the Williamson ether synthesis; reaction with give . Alkyl chlorides readily react with to give substituted . Alkyl chlorides are substituted by softer halides such as the iodide in the Finkelstein reaction. Reaction with other such as azide, cyanide, and thiocyanate are possible as well. In the presence of a strong base, alkyl chlorides undergo dehydrohalogenation to give or .
Alkyl chlorides react with magnesium to give , transforming an electrophilic compound into a nucleophilic compound. The Wurtz reaction reductively couples two alkyl halides to couple with sodium.
Some organochlorides (such as ethyl chloride) may be used as . Tetraethyllead was produced from ethyl chloride and a sodium–lead alloy:
Reductive dechlorination is rarely useful in chemical synthesis, but is a key step in the biodegradation of several organochlorine persistent pollutants.
Some, like carbon tetrachloride and 1,1,1-Trichloroethane have been phased out due to their toxicity or negative environmental impact (ozone depletion by 1,1,1-Trichloroethane).
The most important is dichloromethane, which is mainly used as a solvent. Chloromethane is a precursor to and . Historically significant (as an anaesthetic), but smaller in scale is chloroform, mainly a precursor to chlorodifluoromethane (CHClF2) and tetrafluoroethene which is used in the manufacture of Teflon.
However, the presence of chlorine in an organic compound does not ensure toxicity. Some organochlorides are considered safe enough for consumption in foods and medicines. For example, peas and broad beans contain the natural chlorinated plant hormone 4-chloroindole-3-acetic acid (4-Cl-IAA); and the sweetener sucralose (Splenda) is widely used in diet products. , at least 165 organochlorides had been approved worldwide for use as pharmaceutical drugs, including the natural antibiotic vancomycin, the antihistamine loratadine (Claritin), the antidepressant sertraline (Zoloft), the anti-epileptic lamotrigine (Lamictal), and the inhalation anesthetic isoflurane.MDL Drug Data Report (MDDR), Elsevier MDL, version 2004.2
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