VERFAHREN ZUR HERSTELLUNG VON TRANS-1,1,2,3,4,4- HEXABROM-2-BUTEN (HBB) DURCH BROMIERUNG VON DIACETYLEN

1. A process for the production of trans 1,1,2,3,4,4-hexabromo-2-butene by bromination of diacetylene, characterised in that the diacetylene from the hydrocarbon residue arising in the acetylene recovery operation is dissolved at a temperature of -20 degrees C to + 20 degrees C and a pressure of 1 to 2 bar in a solvent containing a hydroxyl group, initially a mixture rich in vinylacetylene is separated off in a first desorption stage at a temperature of 0 to 30 degrees C and a pressure of 1 to 2 bar with an inert gas, then a gas mixture rich in diacetylene is desorbed in a second desorption stage at a temperature of 0 to 30 degrees C and a pressure of 1 to 2 bar with an inert gas, this diacetylene-rich gas mixture is brominated in a reactor in which excess bromine dissolved in a halohydrocarbon has previously been placed, water optionally being added to the halohydrocarbon, at a temperature of 20 to 40 degrees C and a pressure of 1.2 to 2 bar to form trans 1,1,2,3,4,4- hexabromo-2-butene, gaseous bromine being additionally fed to the reactor with the reaction gas, and the bromine-containing offgas is optionally reacted in an after-reactor with excess diacetylene in a halohydrocarbon.