dehydrochlorination

It is also the main product from the dehydrochlorination of hexachlorocyclohexane.

The process begins with the thermal (600-800 C) dehydrochlorination of chlorodifluoromethane:

The resulting chloro allene undergoes dimerization and dehydrochlorination to give rubrene.

Hexachlorocyclopentadiene is prepared by chlorination of cyclopentadiene to give 1,1,2,3,4,5-octachlorocyclopentane, which in a second step undergoes dehydrochlorination:

Two methods are employed, the hydrochlorination of acetylene and the dehydrochlorination of ethylene dichloride (1,2-dichloroethane).

This reaction is normally done in the presence of an alkali, such as sodium hydroxide, to facilitate the dehydrochlorination of the intermediate chlorohydrin.

The 2,3-chloro isomer is subsequently isomerized to 3,4 isomer, which in turn is treated with base to induce dehydrochlorination to 2-chlorobuta-1,3-diene.

Dehydrochlorination of 2-chloroethanol, developed by Wurtz back in 1859, still remains one of the most common laboratory methods of producing ethylene oxide:

These agents minimize loss of HCl, a degradation process that starts above 70 C. Once dehydrochlorination starts, it is autocatalytic.

Di- and trimercapto tin compounds are used to inhibit the dehydrochlorination, which is the pathway for photolytic and thermal degradation of PVC.

Finally, dehydrochlorination (elimination of hydrogen chloride) of 3,4-dichlorobut-1-ene with dilute sodium hydroxide solution in the presence of polymerization inhibitors gives crude chloroprene.

While extremely useful as a food packaging agent, the major disadvantage of Saran is that it will undergo thermally induced dehydrochlorination at temperatures very near to processing temperatures.

If the different reaction products are easily separated, e.g., by distillation, substitutive free-radical chlorination (in some cases accompanied by concurrent thermal dehydrochlorination) may be a useful synthetic route.

Chlorination of acetaldoxime with N-chlorosuccinimide or chlorine gas in chloroform affords acetohydroxamic acid chloride, which suffers dehydrochlorination with Triethylamine to give acetonitrile N-oxide.

Nitrile ylides can be obtained by the addition of electrophilic carbenes to nitriles, by the photochemical ring opening of azirines and by dehydrochlorination of imidoyl chlorides.

The process consists of three major steps: synthesis of ethylene chlorohydrin, dehydrochlorination of ethylene chlorohydrin to ethylene oxide and purification of ethylene oxide.