Dehydrohalogenation

Some prototypes are shown below: Here ethyl chloride reacts with potassium hydroxide, typically in a solvent such as ethanol, giving ethylene.

One example is provided by the production of vinyl chloride by heating 1,2-dichloroethane:[3] The resulting HCl can be reused in oxychlorination reaction.

One example is the preparation of 1,2,3,3,3-pentafluoropropene from 1,1,2,3,3,3-hexafluoropropane: Chlorohydrins, compounds with the connectivity R(HO)CH-CH(Cl)R', undergo dehydrochlorination to give epoxides.

Some metal-organic coordination compounds can eliminate hydrogen halides,[6] either spontaneously,[7] thermally, or by mechanochemical reaction with a solid base such as potassium hydroxide.

[8] For example, salts that contain acidic cations hydrogen bonded to halometallate anions will often undergo dehydrohalogenation reactions reversibly:[6] where B is a basic ligand such as a pyridine, X is a halogen (typically chlorine or bromine), M is a metal such as cobalt, copper, zinc, palladium or platinum, and Ln are spectator ligands.