(COCl)2 (2 mL) was added to hexacosanoic acid (139 mg, 0.39 mmol) and heated at 70° C. for 2 h, after which time the solution was cooled to rt, and the (COCl)2 removed under a stream of dry argon. The residual volatiles were removed under reduced pressure. The resulting crude acyl chloride was dissolved in THF (0.5 mL) and added with vigorous stirring to a solution of amine 72 (81 mg, 0.18 mmol) in THF/NaOAc(aq) (8M) (1:1, 2 mL). Vigorous stirring was maintained for 2 h, after which time the reaction mixture was left to stand and the layers were separated. The aqueous layer was extracted with THF (3×2.0 mL) and the organic layers were combined and concentrated under reduced pressure. The crude product was purified by column chromatography (10% MeOH in CHCl3) to give amide 73 as a white solid.
