A mixture of 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole (3.0 g, 13.6 mmol), 2-chloroethyl morpholine hydrochloride (4.46 g, 29.7 mmol) and K2CO3 (7.3 g, 2.2 eq) in acetonitrile (60 ml) was heated at reflux for 24 hours. The crude mixture was diluted with DCM and filtered. The solvent was concentrated to an oil (~7.1 g). Purification on a silica gel column (55 g, SiO2, eluted with MeOH:DCM) yielded a solid product weighing 4 g. Recrystallization from hot ethanol yielded 2.1 g (48%), m.p.=131°-132° C.
