n-BuLi (1.6M, 32 mL) was added dropwise to a 0° C. solution of N-t-butylethanesulfonamide (4.0 g, 24 mmoles) in anhydrous THF (80 mL) under dry N2. The solution was stirred for 30 minutes at 0° C. then warmed to room temperature for 30 minutes. It was then cooled back to 0° C. and a solution of 1-bromotridecane (6.4 mL, 25 mmoles) in 10 mL anhydrous THF (distilled from Na--Ph2CO) was added dropwise. The solution was allowed to warm to room temperature overnight, quenched by addition of 1N HCl (60 mL), and partitioned between ethyl acetate and brine. The organic layer was dried, filtered, and concentrated to an oil, which was dissolved in 40 mL of CF3CO2H and stirred overnight at room temperature. It was then concentrated and the solid residue recrystallized from iPr2O to afford 4.8 g (68%) of 2-pentadecylsulfonamide as a light brown (almond) powder. (b) A solution of 2-pentadecylsulfonamide (2.91 g, 10 mmoles) in DMF (40 mL dried over 3Å sieves) was added dropwise to a stirred, 0° C. suspension of NaH (0.5 g, 21 mmoles of hexane washed) in 10 mL dry DMF. The mixture was stirred 30 minutes at 0° C., then warmed to room temperature for 3 hours. It was then cooled back to 0° C. and a solution of 2,6-diisopropylphenylisocyanate (2.14 mL, 10 mmoles) in 10 mL DMF was added dropwise. The mixture was allowed to warm to room temperature overnight, cooled to 0° C., and quenched by dropwise addition of 1N HCl (60 mL). The mixture was partitioned between EtOAc (300 mL) and H2O (100 mL). The organic layer was further washed with brine, dried, filtered, and evaporated to provide an oil which was flash chromatographed (silica gel, 4:1 hexane-EtOAc) to produce 3 g of an oil which solidified on standing (m.p. 65-75° C.).
