is used as a feedstock in the older manufacturing processes for , while the more modern processes use butadiene. The change of raw materials took place in the early 1970s. By 1980, more than 80% of the worldwide production of chloroprene (ca. 0.4×10⁶ tonnes) was manufactured from butadiene. In the USA and in Western Europe, chloroprene is produced exclusively from butadiene, while in Japan a small plant at Denki-Kagaku still uses acetylene.

The traditional chloroprene synthesis is done in two steps. First, acetylene is dimerized to vinylacetylene in an aqueous hydro-chloric acid solution of CuCl and NH₄Cl at 80°C in a reaction tower:

The substantial evolution of heat is controlled by vaporization of water. The C₂H₂ conversion reaches about 18%. The selectivity to vinylacetylene is as high as 90%, with the main byproduct being divinylacetylene. In the second stage, HCl is added at 60°C to vinylacetylene, forming chloroprene:

A solution of CuCl in hydrochloric acid can also serve as the catalyst. The selectivity to chloroprene is about 92%, based on vinylacetylene. The main byproducts are methyl vinyl ketone and 1,3-dichloro-2-butene.

The more recent chloroprene processes are based on butadiene, an inexpensive feedstock. Even though the conversion to chloro-prene appears to be relatively simple and was described early on, it was only after intensive development work by British Distillers and then BP that an economical process was established. This process was first operated by Distugil (50% BP) in a plant with 30000 tonne-per-year chloroprene capacity.

Numerous other processes based on butadiene followed.

In the manufacture of chloroprene from butadiene, the initial step is a gas-phase free-radical chlorination with Cl₂ at 250°C and 1-7 bar to give a mixture of cis- and trans-dichloro-2-butene as well as 3,4-dichloro-l-butene: 

At butadiene conversions of 10-259%, the selectivity to this mixture of dichlorobutenes is 85-95% (based on butadiene). The 1,4-adduct is unsuitable for chloroprene manufacture, but can be isomerized to the 1,2-adduct by heating with catalytic amounts of CuCl or with iron salts.

The equilibrium is continuously displaced in the desired direction by distilling off the 3,4-isomer (b. p.=123 °C compared to 255 °C), allowing a selectivity of 95-98% to be attained.

Processes for the oxychlorination of butadiene have been developed by various firms (ICl, Monsanto, Shell), but there have been no industrial applications.

Chloroprene is obtained with a yield of 90-95% by dehydro-chlorination with dilute alkaline solution at 85 °C:

All recently constructed chloroprene capacity is based on this three-step process, since a direct conversion of butadiene into chloroprene is not economically feasible due to low selectivities.

The autoxidation of chloroprene results in a peroxide which can initiate polymerization. Traces Of oxygen must therefore be carefully excluded during the dehydrochlorination and purification steps. In addition, sulfur compounds, being very effective polymerization inhibitors, are introduced.