A solution of 2-pentadecylsulfonamide (2.91 g, 10 mmoles) in DMF (40 mL dried over 3 Å 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.).
