| 摘要 |
A C6 or C7 diene is obtained by reacting ethylene or propylene with 1, 3-butadiene in the presence as catalyst of rhodium trichloride and treating the catalyst after use with at least one mol. of hydrochloric acid per mol. of rhodium trichloride initially charged before re-use of the catalyst. Ethylene results in 1, 4-hexadiene with some 2, 4-hexadiene, propylene yields 2-methyl-1, 4-hexadiene. The catalyst, usually dissolved in ethanol is used in amounts of 0.000005 to 0.01 mol. per mol. of hydrocarbon (mono-olefin plus diolefin) and reaction is effected at 100-700 p.s.i.g. and 50-100 DEG C. for 15 minutes to 2 hours with ethylene or up to 8 hours with propylene. The mono-olefin is generally used in slightly less than equimolar amounts compared to the diene. Batch or continuous processes may be used. After removal of products, to the catalyst is added 1-40 mols. of hydrochloric acid and preferably 500-25,000 grams of ethanol per mol. of rhodium trichloride.ALSO:Rhodium trichloride, preferably dissolved in ethanol, which has been used as a catalyst in the codimerization of ethylene or propylene with 1,3-butadiene, is reactivated for re-use by the addition to the separated catalyst phase of hydrochloric acid. Preferably 1-40 mols of hydrochloric acid and optionally 500-25,000 grams of ethanol are added for each mol of rhodium trichloride in the separated catalyst phase. |
