Zinc is comparatively an inert element hence is preferred over other metals for dehalogenation of vicinal dihalides. With sodium the dihalide undergoes Wurtz reaction. With zinc the dehalogenation occurs by E2 mechanism. Lone pair of electron on zinc attacks one of the bromine atom , forms a partial bond at the same time C-Br bond is breaking and formin carbon carbon double bond. This transition state the gives alkene.

Other means of removing bromine atoms are sodium iodide or chromous chloride or chromous sulphate or sodium trimethoxy borohydride.