Sodium hydride (0.715 g., 0.0298 mole) is suspended in benzene (30 ml.) and dimethylformamide (30 ml.). Ethyl 7-(methanesulfonamido)heptanoate (6.8 g., 0.0271 mole) (Example O, Step 1) is added and the suspension heated on the steam bath for 15 minutes. After cooling to room temperature, 1-chloro-4-acetoxynonane (6.55 g., 0.0298 mole) (Example A, Step 3) is added over 15 minutes and the resulting solution heated on the steam bath for 20 hours. Then the reaction is poured into water (300 ml.) and extracted with ethyl acetate (3× 100 ml.). The organic layer is washed with brine (2× 50 ml.), dried over sodium sulfate then concentrated in vacuo to an oil which is purified by chromatography on silica gel. The silica gel is eluted with 3% methanol in chloroform and evaporation of the appropriate fraction affords ethyl 7-[N-(4-acetoxynonyl)methanesulfonamido]heptanoate. The yield is 6.0 g. (51%).
