A solution of 0.350 g of benzyl 3-[4-(3-methoxypropyl)-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethoxy]-4-{4-[2-(toluene-4-sulphonyloxy)ethoxy]phenyl}piperidinecarboxylate (Example 267c) in 5 ml of N,N-dimethylformamide is admixed with 0.112 g of 3-phenylpyrrolidine hydrochloride, 0.199 g of potassium carbonate and 0.018 g of tetrabutylammonium iodide. The reaction mixture is subsequently stirred at 80° over 2 hours. The reaction mixture is cooled and poured onto 10 ml of saturated aqueous sodium hydrogencarbonate solution and extracted with tert-butyl methyl ether (2×20 ml). The organic phase is washed with 20 ml of brine, dried over sodium sulphate and concentrated by evaporation. The title compound is obtained from the residue by means of flash chromatography (SiO2 60F). Rf=0.26 (95:5 dichloromethane-methanol); Rt=5.03.
