0.5 ml of oxalyl chloride is added to a solution of 1.2 g of 11-acetylamino-undecanoic acid and 5 drops of DMF in 15 ml of methylene chloride at 0° C. and the mixture is stirred at RT for 3 hrs. The solution of the 11-acetylamino-undecanoyl chloride is treated under argon with 0.6 g of 2-fluoroanisole, cooled to −15° C. and treated with 1.4 g of aluminium chloride. After 2 hrs. at −15° C. the mixture is left to warm to room temperature overnight. The solution is treated with 15 ml of 1M hydrochloric acid at 0° C. and then with 20 ml of water. The organic phase is separated and washed with 1M hydrochloric acid, with water and with saturated sodium bicarbonate solution, dried and concentrated. 1.8 g of N-[11-(3-fluoro-4-methoxy-phenyl)-11-oxo-undecyl]acetamide are obtained.
