Dehydrohalogenation of 3,4-dichloro-1-butene

Claim 1

In a process for directly producing 2-chloro-1,3-butadiene by reacting 3,4-dichloro-1-butene with an aqueous solution containing at least about 15% by weight of alkaline material selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides the improvement of obtaining very substantial increases in reaction rate with a higher percentage conversion and a reduction in the percentage of the unwanted by-product, alpha-chloroprene, by carrying out the process at a temperature of about 0°-100°C and in the presence of from about 0.01% to 10% by weight, based on the weight of 3,4-dichloro-1-butene, of an organic quaternary ammonium compound catalyst in which the nitrogen is attached to four radicals by covalent bonds wherein: a. at least one of the radicals is a (C 6 -C 20 ) alkyl or alkenyl radical or at least two of the radicals are (C 7 -C 20 ) aralkyl radicals, or b. at least one of the radicals is a (C 7 -C 20 ) aralkyl radical having bonded thereto a (C 6 -C 20 ) alkyl or alkenyl radical, or c. at least one radical is an alkyl, alkenyl, or aralkyl radical containing up to 20 carbon atoms and containing a hydroxy or ether group in a position beta to the nitrogen, and d. the remaining radicals are (C 1 -C 20 ) alkyl or alkenyl radicals, or (C 7 -C 20 ) aralkyl radicals.