Production of 1,4-dichlorobutadiene

1,146,493. 1,4-Dichlorobutadiene. IMPERIAL CHEMICAL INDUSTRIES Ltd. 28 Feb., 1967 [24 May, 1966], No. 23151/66. Heading C2C. 1,4-Dichlorobutadiene is obtained by reacting a straight-chain C 4 hydrocarbon or a mixture of such hydrocarbons with hydrogen chloride and oxygen at a temperature above 180‹ C. in the presence of a copper or a copper salt supported on γ-alumina. The catalyst may also contain as co-catalyst a transition-metal salt or complex, e.g. chlorides and chlorocarbonyls, and/or a salt which raises the sublimation temperature of the copper salt, e.g. alkali and alkaline-earth metal salts and ammonium chloride. The reactor effluent may be cooled with water to remove dichlorinated compounds by condensation and the remaining gases may be further cooled to recover monochloro compounds and unchanged hydrocarbons or they may be recycled to the reactor. Specified by-products are 2,3-dichlorobutane, 1,4. dichlorobutene - 2, 2 - chlorobutane, 2 - chlorobutene-2, 3-chlorobudene-1 and trichlorobutene-2-