Method of preparing diolefins containing six carbon atoms by the reaction of ethylene with 1, 3 butadiene in the presence of a catalyst system of ferric chloride, a tertiary phosphine, and a trialkylaluminum

摘要

Hexadienes are obtained by copolymerizing ethylene and butadiene in the presence of (a) ferric chloride, (b) a tertiary phosphine and (c) a trialkyl aluminium. The tertiary phosphine may contain alkyl, aryl, alkaryl, aralkyl or alkyl groups and is used in a mol ratio to ferric chloride 0.1-1.5:1. The mol ratio of trialkyl aluminium to ferric chloride is 1-10:1, and 0.001-0.1 mol of ferric chloride is used per mol of butadiene. Reaction is effected at 0-80 DEG C. with an ethylene pressure of at least 8 kg./cm.2 preferably using a hydrocarbon or halohydrocarbon solvent. The principal product is 3 methylpentadiene-1,4.