Decanoic Acid → 1-Nonene

Participants

Reaction Conditions

Reaction Steps

A mixture of decanoic acid (100 g, 0.580 mol), acetic anhydride (59.2 g, 0.580 mol), dichlorobis(triphenylphosphine)palladium (0.0407 g, 5.8×10-5 mol), and triphenylphosphine (1.52 g, 5.9×10-3 mol) was heated under a slow stream of nitrogen using an oil bath maintained at 255° C. Upon reaching a reaction temperature of ca. 130° C., the acetic acid and/or acetic anhydride distilled out of the reactor into a receiver. When the reaction temperature reached 180°-190° C. decarbonylation initiated, as evidenced by the rapid liberation of gas, and 1-nonene product was distilled from the reactor. The olefin product was removed as rapidly as possible from the reactor. As material distilled from the reactor, it was continuously replaced with an equimolar mixture of decanoic acid and acetic anhydride in a rate that maintained the initial level of the reactor contents throughout the course of the entire reaction. The decarbonylation reaction proceeded rapidly until the reaction temperature reached ca. 245° C. (ca. 40 minutes reaction time), at which point the generation of gas from the reaction had ceased. The reactor was cooled and recharged with another equal portion of Pd-catalyst, heated to 255° C., and the 1-nonene product collected as before. A total of 11 consecutive runs were carried out in this fashion (occasionally adding additional triphenylphosphine as well), using a total of 0.448 g of dichlorobis(triphenylphosphine)palladium and 2.28 g of triphenylphosphine. The combined product was washed sequentially with water, 3N sodium hydroxide, and saturated aqueous sodium chloride, and then dried over anhydrous magnesium sulfate. Distillation afforded 635 g of 1-nonene (bp 144°-145° C./760 torr), which GC analysis showed to be 97.1% of the α-olefin. TON=7885.

Provenance & Evidence