1,3-Butadiene → 1,7-Octadiene

Participants

Reaction Steps

Example 1 was repeated with the same reaction equipment as used in Example 1, except that the composition of the reaction mixture in the reaction apparatus was maintained at 48.4% by weight of sulfolane, 1.23 mole/l of triethylamine formate, 2.1 mg-atom/l of a palladium catalyst (prepared from palladium acetate), 80.4 mg-atom/l (in terms of phosphorus atom) of an organic phosphorus compound (a phosphonium salt synthesized in the zone from lithium diphenylphosphinobenzene-m-sulfonate and octadienyl acetate was used), 3.1 mole/l of butadiene, 0.70 mole/l of octadiene and 0.28 mole/l of triethylamine and that the operation was run under the conditions of a reaction temperature of 60° C. (saturated vapor pressure of butadiene at 60° C. is about 7.4 kg/cm2), a reaction pressure of 6.1 kg/cm2 and a residence time of reaction mixture of 0.83 hour. It was found that the octadiene concentration in the product layer was 2.2 mole/l, the selectivity based on formic acid nearly 100% and that based on the reacted butadiene 95.6%. The ratio between the amount formed of 1,7-octadiene and 1,6-octadiene in octadienes was 89/11. These results show that the rate of formation of octadienes was 0.70 mole/l·hr. The amounts of solvent, catalyst and others eluted in the product layer were, as converted per kg of 1,7-octadiene, not more than 0.6 mg of palladium (as atom), 4 mg of phosphorus (as atom), 144 g of sulfolane and 367 g of triethylamine. Continuous operation was run for 10 days, while there were being added to the reaction apparatus anhydrous azeotropic mixture of formic acid-triethylamine containing formic acid in an mount corresponding to that of formic acid consumed by the reaction, palladium acetate and the phosphonium salt prepared from lithium diphenylphosphinobenzene-m-sulfonate and octadienyl acetate in amounts corresponding to the palladium component and phosphorus component having eluted and sulfolane in the same amount as that eluted. The operation was stable with constant reaction results. Throughout the operating period, no formation of lactones was observed at all.

Provenance & Evidence