isomerisation 3,4 - dichlorbuten - (1) and (dichlorbuten - (2)

摘要

PURPOSE:To obtain a dichlorobutene in high yield, by the mutual isomerization of 3,4-dichlorobutene-1 and 1,4-dichlorobutene-2, in the presence of a highly active isomerization catalyst consisting of a copper compound and a dithiocarbamic acid derivative in a relatively low concentration. CONSTITUTION:3,4-Dichlorobutene-1 and 1,4-dichlorobutene-2 are isomerized in the presence of an isomerizaton catalyst consisting of 0.01-0.3wt% copper compound, e.g. copper chloride or naphthenate, and 0.05-1.5wt% dithiocarbamic acid derivative, e.g. dimethyl dithiocarbamate, of formula I (R and R' are alkyl or aryl; M is H, an atom of a metal, e.g. copper, iron, zinc, Ni, K or Na, or ammonium) or formula II (R'' is alkyl, aryl or a group of a heterocyclic compound). The reaction can be carried out at relatively low temperatures of 90-130 deg.C, with the suppressed decomposition of the dichlorobutene and formation of a tarry compound having a high boiling point as a by-product.