1,1,2,4,4-pentachloro 1,3 butadiene - by dehydrohalogenation of hexachloro 1-butene

摘要

is heated to 10-200 degrees C (pref. 90-165 degrees C) in the presence of a sulphuric halohydrin (pref. 0.5-10 wt. %) in the absence of water, until no more HCl is given off. The product is hydrolysed to give 1,1,2,4,4-pentachloro-1,3-butadiene. The yields are high (70%), method is simple, rapid and selective and only small amts. of easily removed by-product resins are produced.