Stearic Acid → 1-Heptadecene

Participants

Reaction Conditions

Reaction Steps

A mixture of stearic acid (150 g, 0.527 mol), acetic anhydride (54 g, 0.53 mol), and triphenylphosphine (0.921 g, 3.51×10-3 mol) was heated to 220°-230° C. under reduced pressure (55 torr) in a 500 mL flask fitted with a distillation head for product removal. Into this solution was pumped a feed mixture composed of stearic acid (400 g, 1.41 mol), acetic anhydride (150 g, 1.47 mol), dichlorobis(triphenylphosphine)palladium (0.0492 g, 7.03×10-5 mol), and triphenylphosphine (0.921 g, 3.51×10-3 mol) This feed mixture was maintained at ca. 90° C. and introduced into the reactor via a stainless steel tube with the opening positioned below the solution level. As product distilled from the reactor it was continuously replaced with more feed mixture at a rate of introduction that was approximately equal to the rate of product removal in order to maintain a constant level of the reaction mixture. The reaction was continued in this manner until the supply of feed mixture was exhausted (ca. 3.5 hours). At the conclusion of the reaction the level of reactor contents was about the same as at the beginning of the reaction. The distillate product was fractionally distilled to afford 237 g of 1-heptadecene (bp 130°-135° C./0.4 torr) which was found by GC analysis to be 95.6% of the α-olefin. This amount of product corresponds to a catalyst TON of 13,515. Considering the amount of unreacted stearic acid-containing residue recovered in the distillation pot (94 g), the isolated yield of 1-heptadecene relative to the stearic acid in the feed mixture was at least 92%.

Provenance & Evidence